Aquafeed vol 11 issue 4 2019 by Aquafeed Media

Vol 11 Issue 4 2019

AQUAFEED Advances in processing & formulation

MARINE OILS AND PROTEINS Calanus, a new marine resource Mixing in aquafeeds RAS feed production ASC Feed Standard Selenium in antioxidant stress EURASTiP, connecting Europe and Southeast Asia Published by: Aquafeed.com LLC. Kailua, Hawaii 96734, USA www.aquafeed.com info@aquafeed.com

AQUAFEED

VOL 11 ISSUE 4 2019

Contents

MARINE OILS AND PROTEINS 23 Incorporation of marine-based ingredients improves feed efficiency and growth performance. Calanus finmarchicus is a new resource with promising results in aquafeeds.

ASC FEED STANDARD 34

RAS FEED PRODUCTION 15

SELENIUM ANTIOXIDANT CAPACITY 37

The new feed standard will reward farms and feed producers who work towards more responsible aquaculture feed.

How important is the type of extrusion platform used to produce feeds destined for RAS usage.

Trials have shown that providing organic selenium improves antioxidant capacity and ability to cope with stress in fish.

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

AQUAFEED

VOL 11 ISSUE 4 2019

Contents

Interview

News Review

Product Focus 12 Dinnissen vacuum coating technology

13 Feedinamics: an unprecedented tool to calculate the nutritional value of raw materials online

15 Laboratory analysis and lab scale demonstrations highlight extrusion processing conditions critical for high performance RAS feed production

Mixing in aquafeed production

Marine Oils and Proteins

23 A considerable resource of a tiny crustacean - Calanus finmarchicus

27 M arine ingredients in aquaculture feeds

29 K rill performance for all

ewarding responsible production and sourcing: R ASC’s new Feed Standard

Hydroxy-selenomethionine reduces the effects of stress in fish

EURASTiP, bridging the gap between Europe and Southeast Asia

palatability enhancer that improves the performance of A feed pellets in shrimp aquaculture

Columns 21 Peter Hutchinson – Ask the expert

32 Greg Lutz – Trends & developments

39 Soy Aquaculture Alliance

45 Albert Tacon – Recent publications

Calendar of Events

To read previous issues in digital format or to order print copies, visit: http://www.aquafeed.com/publications/aquafeed-magazine/

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

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Entrepreneur, past president of the World Aquaculture Society and co-founder and president of the Global Aquaculture Alliance, Dr. George Chamberlain started his career in aquaculture at Ralston Purina Company, which he joined following his MS and Ph.D. degrees from Texas A&M University. There, he directed Purina’s aquaculture feed program. His journey in aquaculture has led him through work on genetically selected marine shrimp, soy-based feed development and shrimp farming. Dr. George Chamberlain is managing director and co-owner of Kona Bay.

INTERVIEW with George Chamberlain AQUAFEED: To start, would you give us a brief outline of your journey through aquaculture, and how it brought you to where you are today? GC: My career path, probably like that of most people, wasn’t pre-planned. It was the result of fortuitous events and, more importantly, helpful mentors who guided me along the way. It began with graduate research, where I learned the value of sound science. Then, it progressed to the corporate environment, where teamwork and trust were essential. Finally, I engaged in shrimp farming as an entrepreneur, where I felt the satisfaction of working closely with others to build and grow a business. Early on, I enjoyed the opportunity to meet with colleagues and leverage our collective knowledge at annual meetings of the World Aquaculture Society

(WAS). Eventually, I devoted time as a board member and officer of WAS. When harsh environmental criticism fell on the aquaculture community in the mid 1990’s, I helped establish the Global Aquaculture Alliance to refute the exaggerations and guide the sector toward a more sustainable future. AQUAFEED: Certification has become a core activity of the Global Aquaculture Alliance: what impact is it having on aquafeed production? GC: GAA’s Best Aquaculture Practices standards certify each step of the production chain including hatcheries, farms, feed mills, and processing plants. The feed mill standard is driving change by requiring use of responsibly sourced ingredients such as fishmeal, soy, and palm

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

oil. For example, an increasing proportion of marine ingredients used by a given feed mill must come from certified sources or from accredited improver programs. In the latest edition of the BAP feed standard, additional social accountability clauses deal with such issues as labor rights, worker safety and health, and community relations. Stricter controls are emerging to prevent resistance to antibiotics deemed as critically important for human health by the World Health Organization. AQUAFEED: How would you answer those who say that there are too many certification bodies out there and that certification is just too expensive? GC: It is a valid argument that different markets require different certifications, which can result in duplicate costs for producers. An eventual solution for this is Global Seafood Assurances (GSA), which will recognize equivalency among standards that are benchmarked to robust and credible international guidelines for food safety (Global Food Safety Initiative), environmental integrity (Global Seafood Sustainability Initiative), and social accountability (Sustainable Supply Chain Initiative). The GSA is under development with support from GAA. Certification does add cost, because it involves a thirdparty inspector travelling to the facility and conducting an annual audit. We do our best to minimize these expenses by coordinating several audits in a given region at the same time. We also offer more cost-effective group and cluster audits where prerequisite criteria are met. Aside from any investment required for a facility to achieve compliance with BAP standards, the actual cost of the certification audit is only a few tenths of a US cent per kilo of final product. AQUAFEED: Can we talk a bit about Kona Bay? It is arguably one of the largest and most successful suppliers of SPF shrimp broodstock and PLs in the world. Would you put some numbers to that and give a snapshot of the business today? GC: Kona Bay was one of the original shrimp breeding companies that emerged in the mid 1990â&#x20AC;&#x2122;s to commercialize and further improve genetic lines developed by the Oceanic Institute SPF program. It began in a small facility near Kona on the Big Island of Hawaii, but it later expanded to the island of Kauai where it includes a breeding facility, hatchery, farm, and processing plant. One of its major strengths is

its isolation, a critical factor for any SPF breeding program. It is the only shrimp farming activity on Kauai, which is separated from other islands by over 150 km of deep ocean. In 2009, Kona Bay was acquired by Integrated Aquaculture International (IAI), which was started by Ken Morrison, Chris Howell, Donald Lightner, and me. IAI had long experience with shrimp farming in Latin America and Asia. Shortly after the acquisition, Dr. Richard Towner, a highly experienced poultry and fish geneticist, was enlisted to guide the Kona Bay breeding program using family selection coupled with SNP markers, laboratory challenges, and field trials. The program has grown rapidly under the leadership and management of Jim Sweeney, to supply markets for SPF vannamei broodstock throughout Asia. Kona Bay is the largest broodstock supplier to India and Indonesia. The Kona Bay breeding program began with the strategy of offering a single line with balanced traits for growth, disease resistance, and reproductive performance. Now, distinct production systems have emerged in different regions that require more segmented broodstock characteristics including a very fast growing animals (Kona Bay Speed line) for farms with either little disease incidence or high biosecurity; a specific pathogen tolerant animals (Kona Bay Strength line) for farms with high disease prevalence; and a blend of growth and resistance (Kona Bay Balance line) for areas with moderate disease prevalence. AQUAFEED: You have been a big proponent of biofloc systems. Is that how Kona Bay operates? What are the advantages? GC: Kona Bay uses biofloc systems for some of its processes, particularly for growout tanks, raceways and ponds. We use round, plastic lined ponds with center drains, so it is easy to collect solids from the center drain and resuspend them at the top edge to create a floc system. This improves water quality, reduces the need for exchange, and encourages a diverse microflora of beneficial bacteria. AQUAFEED: How does sustainability play out in the genetic development of Kona Bay Pacific White shrimp? GC: In many ways, sustainability is synonymous with resource efficiency, i.e., producing more with less.

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

At Kona Bay, we attempt to improve sustainability by breeding shrimp with faster growth, better FCR, higher reproductive performance, and greater capacity to accept soy-based feeds. Given the concerns about climate change and carbon emissions, we power our breeding center and farm with hydroelectric power derived from rainfall on the central mountain of Kauai. We are committed to the environmental, social, and food safety standards of GAA and are working to achieve BAP certification of our breeding/hatchery facility, farm, and processing plant. AQUAFEED: What has been the impact of the partnership with Hendrix Genetics? GC: Hendrix Genetics is new to shrimp breeding, but they have strong, world-class experience in breeding turkeys, layers, pigs, trout and salmon. They strengthened our programs in animal health, genomic selection, strategic planning, and financial management. With their help we are expanding our nucleus breeding center and our partnerships with regional players. Their experience with salmon facilities, which are generally more advanced than shrimp facilities, helps us leapfrog ahead. We recently engaged with Hendrix Genetics in a partnership with Nutreco (parent company of Skretting) and Ecuacultivos in a breeding/hatchery program in Ecuador. AQUAFEED: Now that Hendrix Genetics has hooked up with Protix in the development of insects, does this mean we will see insect feeds used for shrimp? GC: Kona Bay recognizes that nutrition and genetics are closely linked, so we have maintained an in-house shrimp nutrition program for nearly 20 years. We feel that insect proteins will grow to become a more mainstream component of aquaculture feed ingredients over time, but they are not a nutritionally balanced protein source in themselves. They must be coupled with other ingredients to provide the full complement of nutrients. In most animal feeds, synthetic amino acids are used to balance the amino acid profile, but this doesn’t work well in shrimp feeds due to losses of synthetic amino acids through leaching. Kona Bay has developed and patented a heat-stable form of encapsulated amino acids that enables use of alternative vegetable and animal proteins like insect meal. Another issue that emerges as marine ingredients are replaced by insect meals and

vegetable proteins is loss of attractability of the feed, which affects feed conversion. Consequently, we have also developed a natural attractant mixture that contains no animal ingredients and performs on par with krill meal, but at a fraction of the inclusion level. AQUAFEED: With a background in Black Tiger shrimp, are you planning to introduce P. monodon to the market any time soon? GC: We began breeding Black Tiger shrimp in Malaysia in 2000. We established a subsequent Black Tiger breeding program in conjunction with the Brunei Department of Fisheries in 2006. In 2015, we transferred a portion of the Brunei stocks through quarantine into Hawaii. We are now in the process of growing broodstock of those Kona Bay Black Tiger shrimp in Malaysia for the purpose of conducting field trials next year. If results are satisfactory, we plan to begin commercial sales next year. AQUAFEED: I am seeing Kona Bay shrimp all over the place in Hawai’i these days. Have you expanded shrimp sales to retailers and food service outside the state? GC: We produce 300-400 mt/year of premium, large (30-50 g), head-on food shrimp from Kona Bay broodstock under the brand, “Kauai Shrimp”. These have superb taste and texture and have won numerous cooking contests. We are marketing these on the mainland through distributors and through our website, www.kauaishrimpfresh.com, where they can be purchased fresh from the farm and delivered anywhere in the US overnight. Since the seawater in Kauai is so pristine, we are also marketing Kauai Shrimp as sashimi grade (can be eaten raw) to Japan. AQUAFEED: And lastly, what change, or development would you most like to see in aquafeeds? GC: I am pleased to see the increasing transition to extrusion rather than pelleting of shrimp feeds. Extrusion enables use of a wider range of ingredients including liquids and wheat byproducts with high fiber. It cooks with higher temperature and pressure which improves starch gelatinization, water stability, and digestibility. The capital cost of extrusion equipment is higher than that of pelleting, but the operating cost is often lower, due to savings in raw material costs.

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

NEWS REVIEW Highlights of recent news from Aquafeed.com Sign up at Aquafeed.com for our free weekly newsletter for up-to-the-minute industry news

USDA deregulates Cargill's proprietary canola for cultivation Aquaculture farmers will have access to a sustainable, plant-based source of long-chain omega-3 fatty acids for aquafeed, now that the USDA has deregulated Cargill's proprietary canola for cultivation in the United States. Currently, aquafeed for farm-raised salmon contains fish oil to help fish reach desired EPA and DHA omega-3 fatty acid levels. By combining technology from BASF with its canola innovation capabilities and aquaculture expertise, Cargill is able to provide farmers access to Latitudeâ&#x201E;˘, a

plant-based alternative that relieves harvesting pressure on wild fish populations, while meeting the market need for a reliable s upply of long-chain omega-3s at a predictable price. The company has been testing omega-3 canola varieties under permit in multiple locations in

Montana since 2015, and with USDA deregulation, Cargill plans to advance the commercialization of its long-chain omega-3 canola trait in a tightly-managed closed loop supply chain. The USDA deregulation is an important step in the regulatory approval strategy for Cargill's new omega-3 canola.

CLEAN FEED. CLEAN WATER. Wenger Extrusion Solutions for RAS Feed Production Wenger innovative extrusion solutions deliver clean, durable, nutritional feeds specifically designed for the most efficient RAS operations. Feeds produced on Wenger systems maintain their integrity better and longer, for clean and clear water. So you feed the fish, not the filter. Learn more about the Wenger RAS advantage. Email us at aquafeed@wenger.com today. PHONE: 785.284.2133 | EMAIL: AQUAFEED@WENGER.COM | WENGER.COM USA

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Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Amandus Kahl introduces new fish feed extruder

After 20 years of experience in extrusion systems, Amandus Kahl has developed a new designed extruder in order to meet the increasing requirements of the fast-growing fish feed and pet food markets. The new extrusion product family comes with four different machine sizes covering the whole range of performance from labscale up to 10 t/h industrial largescale applications. All machines are available as machine-only or as turnkey extrusion lines comprising all required process steps like milling and mixing, steam conditioning, extrusion, drying, coating, cooling

and packing. The new extruder comes with the proven Amandus Kahl stop bolt technology for perfect mixing and venting in the first barrel section. Dedicated process zones for compaction, cooking and pumping assure high flexibility and various adjustment options and exchangeable screw elements ensure perfect adaption to changing formulations and quality parameters. These features are complemented by very effective fine-control measures like screw speed adjustment, steam/water addition

to the extruder barrel and individually controllable heating/ cooling jackets - all adjustable during operation for direct product quality response. The combination of individually adjustable screw elements and the described finecontrol measures enable to satisfy its customers’ requirements in the vast majority of cases. Complex and expensive additional equipment to influence expansion behavior is not required, allowing customers to save investment as well as operational costs. During the design process, the main focus was to create an operator-friendly machine. This is achieved by a double-hinge head connection, ensuring fast die changes and fast knife replacement. The frame-mounted touch-screen based operator panel complements the user-friendly design and gives access to all relevant operational data, settings and options during start up and operation. The first series machines are sold to countries in northern Africa and commissioning is expected to be finished in early 2020.

F3 Challenge Launches Carnivore Competition The Future of Fish Feed (F3) third contest – F3 Challenge – Carnivore Edition – is now open to companies that produce and sell “fish-free” feed for farm-raised carnivorous species. Contest registration is open until April 30, 2020. A US$35,000 prize will be awarded in each of three

categories –salmonid, shrimp, and other carnivorous species – to the contestant that produces

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

and sells the most feed made without using wild-caught fish or any marine-animal ingredient. Feeds for all categories must not contain any ingredients consisting of or derived from marine animals, including but not limited to, fish, squid, shrimp, or krill.

UK manufacturer introduces new lumpfish and wrasse diets World Feeds, a UK manufacturer of animal feeds, has entered the aquaculture marketplace with new diets for lumpfish and wrasse. The company that has been producing feeds for ornamental fish, steps into the aquaculture scene with Vita Aqua Feeds (VAF). VAF diets are targeted at one of salmon farmingâ&#x20AC;&#x2122;s biggest issues, the control of sea lice. The company produces feed blocks that are produced using bespoke machinery, designed in-house. Cold-extrusion process is employed producing soft and malleable blocks that are highly digestible and

attractive to the cleaner fish. Crucially, as the blocks maintain integrity in water for up to 24 hours, they encourage and facilitate natural grazing behavior, allowing the larger fish to satiate before the smaller fish take their turn. This subsequently leads to reduced aggression during feeding. The blocks are complete diets and

require no refrigeration or mixing and have a two-year shelf life, massively reducing storage costs and preparation time.

Aller Aqua and TripleNine cooperate on marine raw material development Aller Aqua and marine ingredients producer TripleNine have entered a research collaboration to identify functional components of marine raw materials that benefit fish health and growth. Feeding trials on selected fish species will be conducted at Aller Aqua Research.

â&#x20AC;&#x153;Marine raw materials form the basis of many high-quality fish feeds. In this collaboration with marine raw material expert TripleNine, we are aiming to make maximum use of marine raw materials and their functional components for optimizing feed

performance. Value addition to marine ingredients will also promote the continuous sustainable use of marine resources in fish feed, by making the most out of them,â&#x20AC;? said R&D Director at Aller Aqua, Hanno Slawski.

New shrimp diet to maximize performance and flexibility Shrimp farming has become fiercely competitive in recent years. With farmers increasingly seeking new cost efficiencies as well as ways to differentiate their products in the marketplace, Skretting has developed Xpand, a new diet. The new innovation provides farms with far greater levels of flexibility. Without taking any shortcuts or unnecessary risks, by feeding their shrimp Xpand, farmers can reduce the associated costs and impacts of farming in exposed water locations by harvesting earlier at the same size;

or alternatively, they can choose produce larger sized shrimp within their usual production schedules. The new diet is the result of a four-year innovative R&D conducted by Skretting Aquaculture Research Centre (ARC). Xpand incorporates the investigation and validation of many different ideas. Built on a thorough understanding of the digestive physiology of shrimp, this development focused on three pillars: improved growth, improved nutrition and pond support.

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

PRODUCT FOCUS Dinnissen vacuum coating technology – more than 25 years of innovation

The invention of the vacuum coating process, more than 25 years ago, was an evolution of the Dinnissen Pegasus® Paddle Mixer. In this doubleaxle mixer, the product is raised in a fluidized zone, giving a gentle, fast and energy efficient mixing process. In experiments carried out in a special mixer under vacuum conditions, high concentrations of liquid were sprayed onto the feed pellets. Upon removal of the vacuum, the liquid was drawn deeply into the coated pellets. In this way, Dinnissen succeeded to gradually increase the fat content of pellets up to 42%. The vacuum coating process also helps retain the taste and color of the product and preserve the action of functional additives such as vitamins,

minerals, ameliorators, yeast and enzymes. In a Pegasus® Vacuum Coater, functional additives are introduced after the heating stage, which ensures that heat-sensitive substances remain active after being added to the product. An additional advantage of vacuum coating is that pellets aren’t greasy on the outside anymore. This increases the flow out of the silo, prevents pollution and reduces contamination at farms. The company has improved the vacuum technology over the past few years and made it suitable for many other applications. The Pegasus® Lab Coater, for example, is a great addition to any research department. With this compact and easy-to-clean machine, testing several recipes becomes a much easier task as adding different ingredients and mixing small batches is possible within relative short amounts of time. Nowadays, the Pegasus® Vacuum Coater is used worldwide. Available options such as oversized hatches, hot-air treatment and CIP cleaning make it suitable for many applications. With the latest Pegasus® Vacuum Coater, customers can quickly switch between recipes while still complying with the strictest hygienic requirements.

More information: Dinnissen Process Technology E: powtech@dinnissen.nl

BioMar partners to bring farmed fish closer to end consumers BioMar and French rainbow trout producer Aquadis Naturellement partner to bring a natural and sustainable seafood choice to consumers. The French company’s rainbow trout will be fed with BioMar’s SalveaTM, a new feed concept based on two pillars closer to nature and with a sustainable profile. The new recipe has natural characteristics as it contains naturally derived pigments, added natural antioxidants

and ingredients that resemble natural prey for fish, such as insect meal. It also includes an increased level of the healthy omega-3 fatty acids EPA and DHA, which have proven health benefits for both fish and humans. Together with insect meal replacing part of the fish meal, the SalveaTM recipe also uses fish trimmings meal. This results in a FIFO as low as 0.3, making it very sustainable.

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

PRODUCT FOCUS Feedinamics: an unprecedented tool to calculate the nutritional value of raw materials online After the success found by the INRA/AFZ’s “Tables of composition and nutritional values of feed materials” commonly known as “The Green Book,” the AFZ in collaboration with Ajinomoto Animal Nutrition Europe and the EAAP, published new tables of composition and nutritional values INRA/CIRAD/AFZ in 2017. These new tables are accessible at no charge and can be consulted in English and French at www.feedtables.com. Like “The Green Book”, these new tables allow nutritionists and formulators to know the average nutritional values of more than 300 raw materials according to 260 nutritional criteria. They are based on a database of nearly 3 million values and take into account the latest advances in animal nutrition. These new tables incorporate the latest work carried out at the INRA for establishing the new ruminants feeding system. The given values are part of a statistics regular control and the considerable number of data makes it possible to generate equations of transition between the different parameters when necessary. Although colossal, this work has its limits. Since 2013, the AFZ has wanted to go beyond of what these classic tables offer. The AFZ started a research project to determine from the chemical composition data of raw materials, the equations for predicting nutritional values. The equations are specific for each raw material or group of raw materials which makes possible to determine the composition and the nutritional values for a raw material on demand. This gives formulators the possibility to know the nutritional interest of their own raw materials and not just based on average values. This work was achieved thanks to a research tax credit grant. The only missing piece was to put this tool at the service of users through an online platform. Thanks to A-Systems, software publisher of the formulation software Allix, this RMLINK technology allows the online dynamic calculation of the nutritional values of raw materials. A-Systems puts services online so users can calculate dynamically the values of raw materials through the parameterized equations. Once the raw materials are valued, the user can export the results as a CVS file or, if he possesses a license for the

Allix formulation software, directly access the calculated values without needing to import or export data. Each supplier of the tables of raw materials can thereby have an interactive tool allowing its users to adapt, in terms of parameterized equations, the raw material which he has. From the raw material analysis data entered by the nutritionist into the application, all the relevant equations are activated and allows the user to quickly determine the complete nutritional profile of the raw material. This nutritional profile can then be exported as a CSV file or to a formulation software. This application, from the website www.feedtables. com, will be available on subscription. It will eventually receive valuations of raw materials according to more and more criteria that are adapted to many animal species and integrate regularly to the latest research from around the world. The AFZ wishes to increase the outreach of its knowhow in terms of the qualification of raw materials and put it at the service of the widest possible community of users, both in France and abroad (the application is available in French and English).

More information: Valerie HEUZE (AFZ) E: valerie.heuze@zootechnie.fr https://feedinamics.com/ Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Laboratory analysis and lab scale demonstrations highlight extrusion processing conditions critical for high performance RAS feed production Dennis Funk, Galen Rokey and Kellen Russell, Wenger Manufacturing, Inc.

Physical characteristics of aqua feed pellets have always been important to farmers. For years, high expectations have centered around the requirements of consistent size (diameter), correct buoyance, pellet durability during transportation and handling, and longevity once placed in water. The farmer’s eye and the fish’s consumption rate and efficiency are the top deciding factors on whether a feed’s performance is acceptable or not. These quality demands have been the measuring stick in the aquaculture farming community for decades but are now seen as insufficient due to the rapid growth and requirements of Recirculation Aquaculture Systems (RAS). The reason for this is due to the RAS requirement of constant conditioning and filtering of water in order for the system to maintain the proper balance of oxygen, ammonia, and other water quality attributes. The water quality management systems add a significant cost to the overall operation and investment budget (up to 35%)(1) and require consistent oversight and maintenance as a troubled filter system can result in a loss of the entire tank’s fish stock. Filters capture particles from three main sources – feces, pellet fines or pieces of a disintegrating pellet, and nutrients leached out of the pellet. The feces aspect is impossible to get away from but can be reduced using recipes formulated with creative ingredients to help bind fecal matter, allowing these particles to be more easily and thoroughly removed from the water. This

Figure 1. Laboratory scale RAS testing. Tank on left with high performance RAS feed and tank on right with feed not optimal for RAS.

key capture is handled best in the diet formulation and proper processing steps to improve digestibility. Feed or feed particles and nutrients that are not consumed must also be removed from the recirculated water and can be reduced by proper diet formulation and processing. How can these factors be controlled to minimize a negative role in RAS operations?

Lab trials Recent laboratory analysis and lab scale demonstrations have highlighted the pellet integrity and leaching sources that are best controlled via the extrusion processing step as well as attention to diet formulation. A wide variety of commercially available and laboratory produced floating, sinking and shrimp feeds were tested in a lab scale RAS system. Feeds were manufactured and compared from four major extrusion platforms – single screw, traditional twin screw, conical,

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Figure 2. Turbidity levels were measured over a time period for shrimp feeds made on different extrusion platforms.

and the newest twin-screw models which utilize deep flighted screws and thermal energy for cooking. The studyâ&#x20AC;&#x2122;s aim was to determine which extrusion platform consistently produced the feed most suited to the strict RAS environment. The study not only looked at the long held important factors of pellet buoyancy and water integrity but went further and measured turbidity of the water at measured time intervals as a method to measure how each productâ&#x20AC;&#x2122;s technical qualities would react inside the RAS, and thus have an impact on the filter and waterconditioning system. High water turbidity was indicative of pellets with too many fines and weak durability and became a key indicator for fat and other nutrients leaching from the pellet.

Results Results from the study show the finer and smaller internal cell structure within a pellet as one key influencer of pellet integrity and thus, water clarity. The finer and more numerous cells allow for nutrients to be more tightly secured inside the pellet which significantly limited leaching nutrients. Securing the nutrients inside each pellet has multiple benefits. The fish consumes more nutrition with each pellet resulting in a higher

feed conversion rate and provides the farmer with more production profit. At the same time, the reduction of particles and nutrients in the water can reduce the load on conditioning and filtering systems, resulting in lower filter maintenance costs and less opportunity for filter system failures. The ability of each extrusion platform to produce the finer and smaller cell structure varied significantly. Generally, feed samples made with single screw machines showed the largest and most inconsistent cell structures. These feeds often resulted in the highest level of water contamination once placed into the lab scale RAS systems. This was noticed both by visual appearance and confirmed through turbidity monitors. Feed samples made with traditional parallel shaft twin screw extruders generally ranked better than single screw systems in all aspects of cell structure, integrity in the water and turbidity level. Conical twin screw extruded samples showed consistent cell structure development, high integrity in water and lower turbidity levels than those from traditional twin and single screw platforms. The consistently top-performing feed samples were those produced on twin screw technologies which utilize deep flight geometries and allow for significantly

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

higher levels of thermal energy to replace mechanical energy in cooking the extrudate. These feeds showed unique cell structure development, exceptional integrity inside the water and the lowest turbidity numbers which was easily noticeable by visual inspection of the water. This high-volume twin screw technology coupled with intense preconditioning prior to extrusion resulted in RAS feeds with desirable technical qualities.

Conclusion The conclusion of the lab scale study is that there is significant importance on the type of extrusion platform used to produce feeds destined for RAS usage. While traditional extrusion systems have been able to supply adequate feeds to help RAS farmers develop their markets, true growth in the RAS sector will be facilitated with the highest performing feeds. This will supply consistent nutrients to the fish, reduce the load on conditioning and filtering systems and will in turn reduce the costs of maintaining these systems. Perhaps most importantly, it will mitigate the risks that occurs when conditioning and filtering systems become overloaded and RAS water chemistry becomes toxic for the fish. Advancements in feeds specifically produced for recirculating systems is a critical step in the growth and advancement of the global RAS industry.

References: (1) A Guide to Recirculation Aquaculture, Jacob Bregnballe, 2015, FAO and Eurofish, pg.50.

More information: Dennis Funk Vice President Aqua Feed Division Wenger Manufacturing, Inc., USA E: aquafeed@wenger.com

Galen Rokey Process Technology Director Wenger Manufacturing, Inc., USA E: aquafeed@wenger.com

Kellen Russell Technical Support Wenger Manufacturing, Inc., USA E: aquafeed@wenger.com

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Mixing in aquafeed production Radmilo Čolović, Institute of Food Technology Unlike capture fishery production which is relatively constant, global aquaculture has been facing continuous growth for decades. Consequently, global aquafeed production is growing too and reached approximately 40 million metric tons in 2018 (Alltech Global Feed Survey). The goal of the aquafeed industry is to produce feed with specific ingredient composition and physical shape which will satisfy nutritional and functional needs of specific type and age of aquatic organisms, and thus enable the aquatic organisms to feed efficiently and grow to their full potential. Special attention is given to sourcing of nutritious ingredients and formulation of the diets which will enable efficient production of aquatic species. However, only a homogenous diet would provide all necessary nutrients to the aquatic species. Excess variability in diet composition can have adverse effects on process parameters, product quality as well as on performance of aquatic organisms. The lower the concentration of ingredients, the more difficult it is to achieve mixture homogeneity since some of the ingredients can be dosed in very low

concentrations, such as 10 g/ton. Therefore, mixing is one of the most essential operations in aquafeed production and special attention should be paid to the selection of mixing equipment and optimization of the mixing process.

Mixer selection When selecting a mixer, aquafeed producers should pay attention to the following: • Mixing efficiency should be in line with customer needs and national regulation. • Mixing time should be as short as possible for acceptable mixing homogeneity. • Mixer capacity should be adjusted to the capacity of the other equipment in the line. • Material of construction should be durable. • Mixer should be able to have a quick and complete discharge. • Mixer should have possibility for liquid addition. • Internals and clearances should be designed for easy cleaning.

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Figure 1. CV values for homogenous and inhomogeneous mixtures for the same average concentration of ingredients.

• Mixer size and position should be in accordance with headroom availability. • Mixer price should be acceptable.

Measuring mixing homogeneity Although in the production of aquafeed it is not possible to obtain ideally homogeneous mixture of different ingredients, the goal is to obtain the most homogeneous mixture possible. Mixing homogeneity is estimated by the parameter called coefficient of variation (CV), which indicates how a single ingredient is distributed among the whole batch. The higher the homogeneity, the lower the CV value (Fig. 1). Maximally allowed CV value usually depends on the national regulation and/or requirements of different quality standards. The optimal mixing time is the shortest mixing time for which it gets satisfactory homogeneity, i.e. CV value. If the mixing time is longer than optimal, production capacity of the mixer is decreased, which eventually may decrease capacity of downstream equipment. Also, depending on the type of mixer, prolongation of mixing time can cause de-mixing of the dry mix, with additional use of labor and energy. On the other hand, if the dry blend is not completely mixed, portions of the aquafeed will deviate from prescribed formulation. Mixer types The different mixer types available on the market differ in the mixing principle, such as: • Tumbling type with rotating vessels - motion caused by free fall. • Double ribbon mixers, vertical screw mixers, Nauta mixers - motion caused by thrust. • Mixers with paddles and plows - motion caused by thrust and centrifugal force.

• High intensity turbine mixers - motion caused by centrifugal force. Not all of the listed mixers are occurring in the practice for production of aquafeed. Double ribbon, vertical, and similar mixers were widely used in the factories, but nowadays are mainly used for an onfarm mixing. Typical mixing time for these mixer types is ranging from several minutes up to 20 minutes, depending on the application and legal requirements for homogeneity. These mixers are sometimes struggling with the liquid addition, due to inhomogeneous distribution and caking, and also might have problems when the quick discharge is required. Also, not all of these mixer types are able to reach CV below 5 percent for the ingredients in small dosage quantities (mixing ratio of 1:100.000). On the other hand, these mixers are affordable for even small fish farmers and easy to use onsite. Mixers with paddles and plows, sometimes called fluidizing zone mixers, are typically used in the modern aquafeed production. These mixers can have single or a twin shaft with paddles or plows. The mixing elements are lifting the particles from the center of the mixer trough up the fluidized zone above mixing elements, where mixing takes place in a weightless state, which results in random movement of particles in all directions. Typical mixing time for these mixer types is up to 150 seconds for a dry mixing time (mixing without liquid addition), and these mixers are capable of achieving satisfactory homogeneity and homogenous liquid distribution when liquid is sprayed. Also, these mixers are having quick and complete discharge, since they are typically equipped with “bomb door” for the mixer bottom which is pneumatically opened and closed.

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

mixer types are capable to homogenously mix ingredients differing in the physical properties. One example is how variation of mixing parameters, such as ingredient composition, mixing time and filling degree is affecting CV value of the external tracer added in a concentration of 100 g per ton in the ribbon mixer. It was shown that only after correction of ingredient Figure 2. CV values for ribbon mixer – variation of ingredient composition, mixing time and filling degree. c: corn; s: soybean meal; wb: wheat bran. composition, increasing the mixing time and decreasing the filling degree, CV value drops below 10 percent. Likewise, variation in mixing time, filling degree and liquid addition sequence can affect CV value of external tracer added in the mineral feed in concentration of 10 g per ton in the twin shaft paddle mixer (Fig. 3). The target is to have CV value below 5 percent and not all combinations of parameters lead to the target homogeneity. If the mineral Figure 3. CV values for twin shaft paddle mixer – variation mixing time, filling degree and liquid feed with different physical addition sequence. characteristics is used, it can Mixing parameters be assumed that different results can observed. Besides the mixer types, there are many other Aquafeed producers should assure that only quality parameters which might affect mixing homogeneity, products are delivered to aquatic species and having such as ingredients features like particle density, feed composition in line with the diet formulation is particle shape, particle size distribution, flow properties, one of the main preconditions for that. In order to have electrostatic charge, dustiness, etc.; mixing process desired product uniformity, producers should use the features such as filling level, ingredients’ concentration, appropriate mixing equipment with optimal mixing rotating speed, mixing time, etc.; environmental parameters for acceptable mixing homogeneity. conditions such as temperature, relative humidity. If the particles are similar in size, shape and density, More information: it would be easier to achieve homogeneity of the Radmilo Čolović mixture. However, that is not the case in the practice. Senior Research Associate For example, starch and protein sources have more Institute of Food Technology, cylindrical particle shapes than the fibrous ingredients, Serbia which are more elongated. Also, mineral components E: radmilo.colovic@fins.uns.ac.rs are denser than organic components. Not all of the

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

COLUMN

Ask the Expert Your aquafeed processing questions answered

Q: We have been attempting to produce small diameter fish feeds for hatchery and nursery, but without success. We are not able to keep the extruder running for long and pellets are not uniform. This is an issue I see regularly in plants that are producing standard feeds above 2 mm and then decide to produce smaller feeds. There are multiple process items at stake here, the main one being mash preparation. The key thing to remember, being the rule of thumb, is that all particles must be ground to below one third of die diameter. Die blockage is unforgiving in extrusion processing as there is no mechanical contact with the die surface (unlike pellet milling). If a particle is large enough to partially block a die, this will interrupt flow in that die, reducing the size of pellet emerging from it. Eventually, other particles will build up to block the flow altogether. As this process is occurring, the pressure on the die is increasing, SME is increasing and pellet density starts to decrease. As the process reaches a critical point where dies are almost completely blocked, the SME and shear forces can be so extreme that a high proportion of starches and proteins become damaged, viscosity plummets and density actually increase again, with pellets appearing very ragged and lacking uniformity. The smaller the die sizes, the greater the potential

for blockage, with issues generally increasing significantly below 2 mm die size in a standard extrusion mill. For example, during a production run that lasts 30 minutes and is eventually stopped due to die blockage, the production is not at a steady state and operators will continually make adjustments to account for changes in pellet conformance. Pellet quality from different parts of that run will be highly variable. Due to the tendency to compensate by increasing die open area, there is potential for pellets to be poorly cooked with low SME at early stages of a run and turn out highly destructed or burnt at the end. These two points can be equally damaging to fish health, depending on species. Die pressure is a useful way of determining the pace of die blockage with pressure increasing as the dies block. I would recommend installing a gauge, if you don’t already have one in place, as they are also a useful safety mechanism when integrated into PLC by signaling the bypass gate to open should pressure exceed the manufacturers recommended operating limits. Excess die pressure can result in catastrophic failure. I have seen dies and heads come off with explosive force on occasion with potential for injury. Increasing knife speed continuously due to increasing pellet length is another key indicator

Peter Hutchinson is a Technical Editor at Aquafeed.com, the owner – director of ENH Ltd., New Zealand, and an aquaculture feed consultant. Send your questions to: pete@aquafeed.com

of die blockage, as the same rate of flow is forced to travel through a lesser number of holes. No doubt you have noticed at least some of these issues described, so how do you go about resolving the problem without spending money? You can’t! This problem won’t self-resolve and requires some expenditure. Here is a list of items you will need to work on: Raw material sources are important. Due to fine grind screens and energy required, ingredients that are difficult to grind or have large amounts of fibrous material are less suitable. Fibers which pass grinding and sieving do not fly through the die like an arrow, but

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

will catch on the die edge having an end running into two die holes. This process rapidly builds a bridge, which will clog holes entirely. High levels of hydroscopic powders (such as hydrolysates) in the mash should also be minimized, as they will tend to clog mill screens and sieves. These should be included later in the process in liquid form (i.e. into second mixer, preconditioner or coated). Fine grinding of raw materials is crucial. Historically, this has been done in two stages utilizing a hammer mill as the first stage and a pulveriser as the second stage. Pulverisers work by a process of attrition and do not have a screen in the mill body. They require a secondary cyclonic classifying unit to separate larger particles which escape the milling process and return them for grinding. The process of fine grinding is energy intensive, although improvements in mill design and by-pass milling are making the process more efficient. There are also new hybrid pulveriser designs, which mill and classify in one body and are more energy efficient, potentially doing away with the first stage hammer mill, depending on raw materials/formulation. Sieving is the next vital process step. Whatever sieve design is utilized, it needs to be capable of excluding all particles exceeding one third of die diameter at a rate capable of matching process requirements. Placement of this unit in the process chain is worth considering in order to make the most of eliminating die blockage.

Contamination post-sieving will occur if there is any mild steel or process equipment prone to shedding debris. This contamination can be significant and render any level of sieving virtually redundant. Placement of the sieve directly prior to the extrusion bin is recommended, but with one major caveat. If you are adding any liquids in a second mixing stage, these will most likely blind the sieve, so liquids will need to be introduced post sieve (or the sieve moved prior to the second mixer). Depending on the sieve position, well-placed and effective magnetic separation is a requirement not only to catch rust and prevent die blockage, but to protect downstream equipment from damage caused by larger items such as nuts and bolts. The same goes for scalpers in removing nonferrous items. All liquid additions need to be screened to the same one third of die diameter as dry raw material. Liquids can be a significant source of die blocking contamination and it is all too easy to forget about the importance of screening these. Liquid filters often removed because staff feel they are blocking too regularly. Ensure the filters are sized appropriately to task and arranged in parallel so that they can be cleaned independently during operation. The hand add station needs to be appropriately designed and positioned. If the hand adds are post grinding and sieving, these will almost certainly be a source of die blocking particles. If post

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

sieving, then hand adds will require their own sieving unit. In practice, it is invariably more practical to have hand adds go through the grinding process with the rest of mash. If there are concerns over losses of micro ingredients during grinding, then supplement the rates accordingly. Donâ&#x20AC;&#x2122;t fall into the trap of only using the fine grind equipment when processing small diameter. Once you have contaminated the line with coarse ground mash for larger pellet sizes, it will take a considerable period for this to work its way out of system. Small diameter pellet production favors twin screw extrusion. Twin screw is capable of 3-5 times the rate of single screw, with much greater control over density and uniformity. Although a twin screw wonâ&#x20AC;&#x2122;t resolve all the issues described above, dies will block just the same if the mash is not appropriately ground! The die open area needs to increase progressively below 2 mm due to increased surface area to volume in the die creating increased restriction flow. Floating feeds below 1 mm become increasingly challenging and will often require an adjustment of formulation to increase starch. There are some aspects to drying feed with small diameters which create further dilemmas, but that will need to wait for another column. Good luck with your further attempts at producing small diameter feed and we look forward to your feedback on how you are progressing!

MARINE OILS AND PROTEINS

Figure 1. Calanus finmarchicus, the largest renewable resource in the Norwegian Sea.

A considerable resource of a tiny crustacean - Calanus finmarchicus Isak BĂ¸gwald and Hogne Abrahamsen, Calanus AS The marine zooplankter Calanus finmarchicus is the largest renewable and harvestable resource in the Norwegian Sea (Bergvik et al., 2012). It is a free-living copepod with a life cycle of one year and is the key food source for most of the commercially important fish stocks in the North Atlantic. Due to a favorable size of 2-4 mm of the adult copepods, and a primary composition of protein and lipids, C. finmarchicus is the optimal natural starter feed for larvae of marine fish and shrimp. C. finmarchicus spends most of its life in deep ocean waters, but in the period between April and August the copepods aggregate close to the ocean surface (HĂ¤fker et al., 2018), and this is when the harvesting takes place.

The annual biomass production of C. finmarchicus and closely related species in the Norwegian Sea and adjacent oceans is in the range of 200-400 million metric tons (Skjoldal, 2004), way above the total biomass of all fish species in the same area (Fig. 2). It is generally recognized that only between 10-15 % of the energy is being incorporated as biomass when moving upwards from one trophic level to the next in the ecosystem (Lindeman, 1942); the rest is lost largely through metabolic processes as heat. The largest biomass is found at the base of the food pyramid and to utilize resources such as zooplankton is thus ecologically efficient and bioeconomically desirable, especially when considering the uncertainty and present exploitation of

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Figure 2. Estimated standing biomass and annual production of various marine species, compared to total global and Norwegian aquaculture and fisheries (Skjoldal, 2004; FAO, 2018).

many of the global fisheries (FAO, 2018). The Norwegian company Calanus AS has been working on the utilization of this vast resource for the last 15 years and has developed a completely new industrial value chain which includes the development of unique harvesting technology, innovative production process, brand-new product range, regulatory clearances, documentation and commercialization of products derived from C. finmarchicus. The company has the advantage of being the first-mover in a market that is being developed by investments from both industry and governmental organizations in Norway.

Sustainable harvesting is a collaborative effort The development of sustainable harvesting practices of C. finmarchicus is a collaboration between the industry, research institutes and authorities in Norway. In 2019, the government opened commercial harvesting of C. finmarchicus, with an initial quota of 254,000 metric tons per year. This quota is 0.5 percent of the standing biomass, a clear statement of the precaution taken to secure sustainable harvesting practices considering the standard precautionary quota is ten percent of a standing biomass. Calanus AS has developed proprietary technology for the harvesting of C. finmarchicus in close collaboration with fishing companies, engineering companies and equipment suppliers. The technology includes a patented and specialized harvesting technique for

Figure 3. Harvesting C. finmarchicus in the Norwegian Sea with the patented CalanusÂŽ harvesting technology.

C. finmarchicus which, together with innovative onboard handling techniques, ensures fresh raw material with low bycatch rates. The company is certified for The Global Standard for Responsible Supply (IFFO RS), highlighting their commitment to responsible practices in the areas of raw material procurement and food/ feed safety.

An innovative, effective and gentle production process Several years of research and development has led Calanus AS to a manufacturing process for C. finmarchicus whereby extraction of both oil and proteins can be done in a highly effective and gentle manner, keeping the natural bioactive properties of the copepods intact. This knowledge has been adopted and implemented in the industrial production process

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

production plant which will increase the future production capacity up to 12-fold compared to the present capability. It will be the world’s first full-scale industrial plant for bio-refining of C. finmarchicus, located near the Arctic Circle in the city of Sortland, Norway.

Figure 4. Calanus AS has developed an innovative production process, free of solvents and additives.

of C. finmarchicus, which is free of solvents or additives, and forms the basis for the products from Calanus AS. The copepods have extremely low levels of environmental pollutants due to their short life cycle and rapid turnover rates, eliminating the need for further processing of the products. The company is currently building a new industrial

Novel products with bioactive properties The production process yields three products; Calanus® Hydrolysate, Calanus® Powder and Calanus® Oil (Fig. 5). While the oil, with its unique wax ester omega-3 composition (Tande et al., 2016), is utilized almost exclusively for human supplement applications, the two other products are becoming attractive ingredients in formulated feed for aquaculture. Calanus® Hydrolysate is an enzymatically hydrolyzed liquid protein product, heat stable and very soluble with a natural marine flavor. The molecular weight distribution of the hydrolysate reveals mostly small peptides, thus making the product highly digestible which is especially important for shrimp and juvenile fish with an underdeveloped digestion system. Approximately 99% of the peptides are < 6000 Da, covering the range of most bioactive peptides consisting of 2-20 amino acids. Bioactive peptides are known to influence appetite regulation, growth and development, immunity and survival, stress and behavior, as well as a wide range of other metabolic pathways (Daliri & Lee, 2017; Möller et al., 2008; Sanchez & Vazquez, 2017; Wang et al., 2016).

Figure 5. Calanus® Oil, Calanus® Powder and Calanus® Hydrolysate.

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Figure 6. C. finmarchicus in the digestive system of L. vannamei at PL-9, easily visible with its deep red color.

The favorable molecular weight distribution, together with an optimal amino acid profile and flavor-enhancing properties, make the product perfectly suited as an ingredient in aquaculture feed for marine fish and shrimp larvae. CalanusÂŽ Powder is the solid component resulting from the production process, mill-dried into a homogenous dry meal and its main constituents are hydrolyzed proteins and peptides, a lipid fraction and chitin from the processed shells. Naturally, as it is a product of the same process as the hydrolysate, the proteins and peptides in the powder possess a molecular weight distribution and amino acid profile comparable to that of the hydrolysate. With an abundance of essential amino acids for fish and shellfish, the product contains high amounts of methionine, lysine and arginine. These are generally the first limiting amino acids of commercial shrimp formulae (Fox et al., 2006). The lipid fraction is an important source of energy and essential fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the most important fatty acids for growth in shrimp (Glencross and Smith, 2001). Dietary chitin has been shown to stimulate the innate immune system of fish (Esteban et al., 2001) and shellfish (Wang et al., 2005) and positively affect growth in shrimp (Rodolfo et al. 2017). This can be explained by a more effective molting process considering the structural role of chitin in the shells. The powder also

contains the powerful antioxidant astaxanthin for increased growth and pigmentation (Ju et al., 2011; Song et al., 2016), and minerals selenium and zinc for increased growth and survival (Sritunyalucksana et al., 2011). In addition to the abovementioned feed ingredient products, whole animals of C. finmarchicus are suitable as complete feed in aquaculture. C. finmarchicus is a rather large copepod and its size and composition make it perfect for shrimp post-larvae (PL) and fish larvae and juveniles. Initial feeding trials with L. vannamei show that C. finmarchicus is an accepted and highly attractive feed (Fig. 6). The trials found the copepods were optimal as feed from PL-4 (consuming 90% of the copepods at this stage) and onwards, where it can function as a replacement for Artemia until the shrimp is ready for formulated feed. The shrimp feeding on C. finmarchicus were also larger in size compared to the control with Artemia. Further ongoing trials aim to optimize the protocols in regard to volume and starting point, possibly using C. finmarchicus in complement with Artemia in stages PL-1 to PL-3. The company is currently involved in multiple feeding trials, testing both whole animals of C. finmarchicus and its products as feed ingredients while aiming to demonstrate the advantages of using natureâ&#x20AC;&#x2122;s own starter feed in the aquaculture of marine fish and shrimp. References available on request.

More information: Isak BĂ¸gwald Researcher Animal Health & Nutrition Calanus AS, Norway E: isak.bogwald@calanus.no

Hogne Abrahamsen Head of Sales and Marketing Animal Health & Nutrition Calanus AS, Norway E: hogne.abrahamsen@calanus.no

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

MARINE OILS AND PROTEINS

Marine ingredients in aquaculture feeds Sara Magalhães, Sorgal It is widely known that the incorporation of marinebased ingredients into the diets of farmed fish and shrimp increases feed efficiency and promotes fish growth performance due to an ideal nutritional profile (and therefore enhanced nutrient digestibility) and better feed palatability. It also produces a more natural, “fish-like” taste to the final product approaching farmed fish to the wild specimens. Fishmeal (FM) and fish oil (FO) are quintessential marine ingredients in aquafeeds and the most widely used in both freshwater and marine species. They supply, among others, the essential amino acids and fatty acids (FA) required by fish for the best health and growth performance reflecting in the wild diet of these animals. An essential nutrient is one that is not synthesized within the animal body (or at a sufficient rate to meet the physiological requirements of the animal); therefore, their supply is mandatory in the diet. The biggest issue related to the use of FM and FO is that about 65-75% of these ingredients are produced from the harvest of small pelagic fish (anchovies, herring, menhaden, sardines, among others) mainly in South America. The other 25-35% come from the co-products produced after fish processing for human consumption (SEAFISH, 2018). Therefore, this situation categorizes FM and FO as non-environmentally sustainable ingredients and inputs to fish production a high carbon footprint and fish in–fish out (FIFO) ratio. In fact, FM and FO that have been produced from reduction fisheries have an environmental cost linked to natural resources exploitation, transformation processing and transporting ingredients. Given this, research performed over the last years has been devoted to finding more sustainable and affordable non-marine ingredients that can be included in fish feeds. Meals and fats/oils from terrestrial animals, as well as vegetable ingredients, have been under evaluation as protein and lipid sources in the

diets of several species (Glencross et al., 2007; Caruso, 2015; Henry et al., 2015; Campos et al., 2017, 2018a,b, 2019; Monteiro et al., 2017; Reis et al., 2019). The total or partial replacement of marine-based ingredients by such alternative raw materials is possible, provided the essential nutrients are present in the feed in sufficient quantities to meet fish daily requirements, in order to achieve good growth, overall health and fillet quality. While sustainability is a major topic when discussing ingredients (alternative, locally available) and overall fish production, the final consumer increasingly searches in the fishmonger for fish presenting features close to those of a wild fish, mainly related to flavor, visual aspect (color, freshness, brightness) and n-3 FA content (EPA and DHA). This brings us again to the pertinence of marine ingredients in the diet of cultured fish. Besides FM and FO, whose inclusion levels in fish feeds have been declining worldwide over the years (FAO, 2018), other marine ingredients (meals, hydrolysates and oils) are worth noting. These protein and lipid sources are usually included at quite lower levels than FM and FO and can be used for different purposes rather than nutrition itself. Table 1 summarizes the characteristics of the main marine ingredients with potential use in fish feed formulations.

AQUASOJA’s approach Since 1993, AQUASOJA, a brand within SORGAL (a company belonging to SOJA DE PORTUGAL Group), has focused on the development, production and marketing of integrated feed solutions for aquaculture species. As above mentioned, reduction fisheries directed towards the production of FM and FO are not sustainable in the long term. SAVINOR UTS (another company belonging to SOJA DE PORTUGAL Group), located close to the Portuguese Atlantic Coast, produces high quality, fully traceable ingredients, that are mainly derived from local canning industry by-products and local harbor whole fish (tuna, sardine, mackerel) and

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Table 1. Brief characterization of the main marine ingredients with potential use in fish feed formulations.

are included in AQUASOJA recipes. This synergy allows AQUASOJA a regular supply of FM and FO, enabling formula stability in terms of quality and price. It also provides a better control on quality, freshness and traceability of these raw materials while increasing the sustainability of the fish feed production (ensuring a low FIFO ratio). SAVINOR UTS collects, treats and valorizes 100% wild-caught fish. Fishmeal used in AQUASOJA feed is therefore of high quality, presenting easily digestible proteins and main vitamins and minerals. Moreover, FO and FM produced in SAVINOR UTS are excellent sources of healthy n-3 FA such as EPA and DHA. The valorization of marine co-products for inclusion in farmed fish feed reflects AQUASOJA’s economic and environmentally sustainable practices and illustrates SOJA DE PORTUGAL Group’s commitment to a circular economy. 15.00 [381]

In addition to FM and FO, a considerable part in every feed, AQUASOJA also includes in its recipes other marine ingredients, such as fish and crustacean meals and hydrolysates, with the purpose of enhancing feed palatability and adding functionality to both functional and conventional feeds. References available on request.

More information: MAX.

393.31 [9990]

Sara Magalhães Technical Manager, AQUASOJA Sorgal, Portugal E: sara.magalhaes@ sojadeportugal.pt

67.28 [1709]

30.00 [762]

19.16 [487]

64.83 [1647]

108.59 [2759]

ALL FROM A SINGLE SYSTEM

BIN Inlet

P.O. Box 8 100 Airport Road Sabetha, KS 66534, USA Phone: 785-284-2153 Fax: 785-284-3143

MIN.

29.19 [741]

39.00 [991]

101.44 [2577]

30.38 [772]

31.19 [792]

MIN.

F085 SHIMPO

36.91 [937]

MAX.

391.31 [9939]

Ă12.00 [305]

DCC Inlet

End of Head

CYL. Disch.

15.00 [381]

With Extru-Tech’s ADT (Advanced Densification Technology), the possibilities are far reaching. ADT technology gives you the option to produce sinking feeds with excellent consistency and density. That same ADT technology can produce floating

FROM SINKING TO FLOATING

feeds with high protein characteristics … all from a single extrusion system. 269.88

In the aquafeed business, you either sink [6855] or swim. Contact Extru-Tech today at 785-284-2153 or visit us online at www.extru-techinc.com

284.00 [7214]

278.03 [7062] 1.93 [49]

extru-techinc@extru-techinc.com www.extru-techinc.com

199.38 [5064]

18.00 [457]

1.00

P.O. NPT Box 8 • 100 Airport Road • Sabetha, KS 66534, USA Phone: 785-284-2153 • Fax: 785-284-3143

12.56 [319]

15.88 [404]

24.59 [625]

03 54

256T

108.28 [2750]

2.00 NPT [STEAM]

3/4 NPT

2.00 NPT

12/13/18 12:00 PM

80 NORGREN

88.00 [2236]

160

MAXUM SIZE 10

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019 102.13 [2594] 111.12 [2822]

52.19 [1325]

48.00 [1219]

57.69 [1465]

ET-296i.indd 1

1.00 NPT [STEAM]

2.00 NPT [WATER]

53.25 [1353]

66.50 [1689]

Krill performance for all Tibiabin Benitez-Santana, Aker BioMarine AS

Sports performance is exactly what it sounds like. It is training designed specifically to improve an individualâ&#x20AC;&#x2122;s performance within their sport, including any bodily activity that enhances or maintains physical fitness and overall health and wellness. This means that endurance exercise adheres strictly to the principle of specificity: the body will adapt in direct relation to the stressors placed on it. So, move, eat, rest, repeat makes for a decent training plan, up to a point. However, if you want to maximize your performance gains, eventually you need to train smarter: smarter movement, smarter eating and smarter recovery. Believe it or not, this advice works not only for aspiring athletes but also for manâ&#x20AC;&#x2122;s best friend â&#x20AC;&#x201C; the dog and farmed aquatic animals (fish and shrimp) alike.

Smart training with krill Athletes use nutritional strategies to improve their training and performance through increasing their metabolic capacity, delaying the onset of fatigue, and improving muscle hypertrophy by enhancing recovery, improving immune function, and decreasing oxidative stress. Krill oil is rich in long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which have been found to reduce inflammation and have positive effects on the cardiovascular system. A recent study indicates that krill oil may support immune function in young adults after heavy exercise. Aker BioMarine is dedicated to studying the effects of krill on humans,

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

pets and farmed fish and shrimp. Several human clinical trials have shown that krill oil supplementation leads to an increase of omega-3 index. Maintaining optimal omega-3 levels may be important during the recovery phase after intense exercise. It is important to keep in mind that lower omega-3 levels have been associated with increased risk of illness, which may cause training disruptions. For this reason, it is important to have a good source of omega-3 fatty acids, such as krill oil, when engaging in intense training. You might wonder how professional athletes are related to animal performance. Well, we all want to perform: athletes, sled dogs and even salmon. The connections are actually more related than what you might think, as nutrition plays an important role for all of us. Aker BioMarine has identified four positive krill effects across these species when it comes to performance: inflammatory response, heart health, well-being and muscular system.

the Iditarod sled dog race, can induce inflammation and generate muscle damage. In order to increase our krill knowledge on dogs, Aker BioMarine conducted a study on the animals in the Iditarod trail sled dog race, the hands-down toughest annual long-distance sled dog run. In this project, we found that five-week krill meal supplementation of sled dogs before the race led to higher amounts of omega-3 polyunsaturated fatty acids consumed, and therefore a higher omega3 index at start of race. A higher index is associated with a significant reduction in the exercise-associated rise in inflammation and a tendency to minimize the level of muscle damage. This is linked to the human results, where krill plays an important role keeping the omega-3 levels up during endurance performance. The results of this study are encouraging for krill meal supplementation for dogs in general, whether they are performing in long distance races or taking their leisurely afternoon walk.

Keeping dogs up and running Sled dogs for example, have a high metabolic energy expenditure during endurance exercise, and it has been shown that repetitive endurance exercise is associated with lipid peroxidation and reduced plasma antioxidant concentration. Excessive free radial production induced by an extreme exercise challenge, such as

Improved swimming performance, better fillet quality But what about salmon? The physical, nutritional and sensory properties of salmon meet at the point of human consumption and are influenced by the dietary raw materials. It is therefore important to monitor and understand the effects on fillet quality when novel

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feed ingredients such as krill meal are introduced. Thus, improved knowledge on the effect of alternative feed resources is required during the finishing period before harvesting when the impact on salmon flesh quality properties is most significant. During the past decade, the effect of krill on salmonids health and fillet quality has been investigated. Fat content, fat distribution and fillet quality are the major quality criteria that dictate the market value of salmon fillets, which may all be influenced by feed composition. Due to krill inherent advantages i.e. feeding stimulants, omega-3 fatty acids bound to phospholipids and highly digestible peptides, there is an improvement in firmness and integrity (less gaping) by krill meal-supplemented salmon finishing diets, showing a significant correlation with a range of biochemical and molecular factors, supporting that salmon fillet integrity is multifactorial with complex biological interactions. What is curious about fish is their swimming exercise, in other words, their performance, which increases the muscle growth and flesh quality. Fish are known for their great capacity for aerobic, sustained swimming, and anaerobic, burst swimming. Swimming activity in fish is accomplished through the activation of the skeletal muscle, the largest tissue in the animal, representing more than 50 percent of its body weight. Skeletal muscle in fish is composed of two functionally and anatomically separated types of muscle. Flesh quality in salmon is the result of a combination of characteristics of skeletal muscle, which include the muscle chemical composition (fat content and fatty acid profile, glycogen stores, oxidative stability, color) and muscle cellularity and is strongly influenced by a variety of extrinsic factors such as feeding, pre- and postslaughter handling, processing, and storage procedures.

Since salmon farming is the production of high-quality food, it is vital that the fillet quality is in accordance with consumersâ&#x20AC;&#x2122; expectations. Visual appearance is the most important property of foods in determining their selection to actual consumption. Salmon with insufficient firmness are downgraded, leading to severe economic losses to the farming and processing industries. One of the major criteria of flesh quality is texture, which is determined by muscle cellularity (fiber number and distribution) and connective tissue characteristics, where collagen is a major determinant of salmon fillet quality. Different studies have shown an improvement in gaping and fillet firmness and a decrease of melanin spots in salmon fed krill diets, which are key requirements for the salmon industry. These results relate to humans and dogs, where the omega-3 phospholipids of krill play an important role in reducing muscle inflammation. In short, there is scientific evidence on the benefits of krill across the three species when it comes to performance. Humans, dogs and salmon performance can benefit from krill, with their daily feats of biking, running and swimming endurance increasing. The results are related, and we need to start looking at the evidence and find ways to share it.

More information: Tibiabin Benitez-Santana Director R&D, Fish Nutrition Aker BioMarine AS, Norway E: tibiabin.benitez-santana @akerbiomarine.com

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Trends and developments C. Greg Lutz, Ph.D. Aquaculture intelligence… the new A.I.

I often find myself bouncing around the internet when I’m supposed to be ‘working.’ But, in a way, I really am working because I stumble on many aspects of modern life that relate to aquaculture in one way or another. The pace of technological innovation seems to accelerate almost daily, and ‘technology’ (one of those catch-all terms, kind of like ‘scientists’) is advancing in too many areas for any of us to keep track of. Many times, these advances seem far removed from day-today life on a fish farm. To date, technology hasn’t really impacted things like harvesting, loading out hauling trucks or workboats, or collecting, recording and disposing of mortalities. Nor has it eliminated

the need to check the oil and radiator fluid in tractors or generators. Nonetheless, technology is increasingly offering us new ways to approach aquaculture production. In the late 1980’s, my friend Walter Landry told me that we would never be able to raise fish profitably with automated systems, because “someone needs to be with them and observe them day in and day out.” Walter served as president of the Striped Bass Growers Association and the Louisiana Aquaculture Association, and also served on the board of the National Aquaculture Association, so as a young extension specialist I took his opinion more or less as gospel. Three decades back, when someone brought up the topic of artificial intelligence (AI) in aquaculture, more often than not they were referring to simple monitoring and control apparatuses, like an oxygen sensor that sent a continuous signal to a computer, that in turn would open an oxygen bottle solenoid valve or turn on an aerator if DO values dropped

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Dr. Greg Lutz is a Professor with Louisiana State University Agricultural Center. He is also an author and consultant, and serves as the Editor in Chief of Aquaculture Magazine. E: lutzaqua@att.net

below some pre-set level of concern. This type of ‘innovation’ fit in well with the traditional production process and reduced the potential for human error (um… err… or, at times, simply substituted that risk with the potential for technological/mechanical error). Systems were soon developed that deployed any number of sensors that could be connected (by wires and state-of-the-art interfaces) to a computer, allowing a manager to monitor water quality and equipment performance from multiple systems in real time. With their bundles of wires reminiscent of sticky spaghetti, these packages were impressive to look at and fun to show off to visitors (especially when purchased with someone else’s money), but they were still just data … just numbers and on/off signals. The emergence of the internet

allowed personnel to view realtime facility data from far away locations, but this was not much of an improvement (especially if you had to get up at 3 am and drive for an hour to try to respond to an equipment failure). Tedious data entry, manipulation and interpretation was still required to turn the numbers generated by these monitoring

systems into management tools for evaluation, troubleshooting and planning purposes. But all the while, AI was evolving as it were. If you could pull together and package the mountains of data related to feeding rates, mortality patterns, water quality, growth rates, and equipment performance, programs that could gobble up the numbers and spit out

enlightened conclusions were beginning to be available. This level of interpretation was perhaps not yet a practical tool, but all that would soon change… with the dawn of the Internet of Things (cue dramatic music…). Yes, IoT. The Internet of Things. I still don’t really grasp it, but I guess my understanding of IoT involves someone asking Alexa to turn on the coffee maker. … I guess. I ignored the whole concept (as much by ignorance as by choice) for as long as I could, but in addition to changing so many aspects of our modern life – IoT has opened up a whole new frontier of production (and business strategy) management for all sorts of manufacturing, including aquaculture. Look up the term “Industry 4.0” sometime. The capacity for modern sensors and monitors to communicate through wifi and internet channels has reshaped the potential architecture for ‘command and control’ in aquaculture operations. And more importantly, the computational resources required for interpretation, decision-making and long-term planning can now be fed a continual diet of all types of data, allowing subtle relationships between management factors and production strategy trade-offs to be clearly understood. As advances in AI continue, many aquaculture production systems really will be able to operate with minimal human supervision. I’m not sure whether Walter would be sold on the idea that a computer could understand our fish better than we can, but we’ll see how it all works out in the coming years.

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Rewarding responsible production and sourcing: ASC’s new Feed Standard Michiel Fransen, ASC As you read this, ASC is finalizing the new ASC Feed Standard, a project that is hugely important for the industry and a standard we think will encourage and reward farms and feed producers who work towards more responsible aquaculture feed. The production of feed’s raw material can have a long and complex supply chain, and can include social and environmental issues throughout the process. These can include habitat loss, over-harvesting, biodiversity impacts, pollution, poor labor conditions, human rights abuses and lack of community consultation, among others. Many of these issues are already addressed by requirements in ASC’s individual species standards, but ASC believes that aquafeed is an area that requires a comprehensive separate standard that can give all of these issues the attention they deserve. Readers of Aquafeed.com will know, better than most, the trends in feed production that are shifting towards a decreasing proportion of marine ingredients in feed over time. But the replacement ingredients aren’t just the headline-grabbing insect-derived proteins – they include a growing proportion of land-based plant ingredients. As the diversity of ingredients increases, so too do the challenges of ensuring they are also responsibly produced and sourced – all while awareness of the importance of responsible sourcing spreads among farmers, retailers, as well as consumers. ASC recognizes the opportunity here to help meet the growing demand for more sustainable feed and to satisfy the need to show how an increasingly complex industry and supply chain can be organized in a manner that will have multiple benefits, both in and out of the water. The ASC Feed Standard will help feed producers and farmers not only work towards more responsibly sourced feed, but also to be able to easily demonstrate

this commitment to their customers and stakeholders. In other words, we aim to bring the benefits of ASC certification currently enjoyed by farms to feed mills as well.

Standard development It might be helpful to start with some information on how the upcoming standard was developed, because organizations that embrace and work towards the requirements in the standard deserve an assurance that they were developed carefully, collaboratively and using the best science. Proper governance is an integral aspect of the ASC program. At multiple points during the development process the Feed Standard steering committee, a multi-stakeholder group whose members include representatives from the feed mill industry, feed ingredient industry, farm industry, NGOs and retail, provided essential additional expertise and guidance. This year saw the successful final meeting of the Standard’s steering committee and the standard is now ready for final approval. The Standard is now awaiting final sign-off from the ASC supervisory board and technical advisory committee. While these two bodies have oversight of all ASC standards, a lot of work from ASC staff and stakeholders goes into developing each standard. As with all our standards, the Feed Standard was widely shared on our website for public consultation. After reviewing

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the input we received from stakeholders, it was revised based on the responses, and then published for public consultation for a second time. Following that second round of consultation, the standard underwent through further revision.

Crop-derived ingredients One important area of the new standard is the increased focus on crop-derived ingredients. The sustainability discussion of feed ingredients has traditionally focused on marine ingredients, and although there are environmental and social concerns there that need to be addressed, aquafeed is composed of far more than what we take from the seas. The diversity and scale of environmental and social impacts related to crop-derived ingredients are at least equal to marine ingredients, and in some cases even more significant. The ASC Feed Standard will be the first in the industry to recognize this and will include specific requirements on crop-derived ingredients – including soy, wheat, corn, rice, and canola. We look forward to publishing the detailed content of the Standard once it has been formally approved by the ASC supervisory board, and it will address a number of initial priorities related to crop-derived ingredients: transparency on origin and requirements to source from production areas that are at low-risk of illegal deforestation. It will also require feed mills to work towards deforestation-free supply chains over time. Marine ingredients This doesn’t mean ASC has forgotten about the importance of responsibly sourcing marine ingredients – this is a critical issue for the aquaculture industry to address and the new ASC Feed Standard provides a framework for feed mills to do just that, make improvements where necessary, and demonstrate their responsibility to the wider industry. The ASC Feed Standard addresses marine ingredients through a global improvement model that requires feed mills to source marine ingredients from fisheries demonstrating increasing levels of sustainability and eventually MSC certification. There are many impacts that are relevant to all feed, whether from land or sea. The Feed Standard includes requirements on these issues that have become increasingly important to consumers, retailers, NGOs,

and many other concerned stakeholders. These issues include GMOs, greenhouse gas emissions and water usage, to name a few.

Feed mills certification The principles, criteria and indicators of the Feed Standard will be verified at the feed mill level. Feed mills will be able to apply for certification against the Feed Standard, and ASC certified farms will need to source feed from mills which are certified against the Feed Standard. Mills will need to have a Responsible Sourcing Policy to demonstrate policies and management processes are in place relating to sourcing of all types of ingredients that represent more than one percent of total ingredients by weight. This must also include a commitment to continuous improvement in relation to the sustainability levels of the primary sources of the ingredients used for the manufacturing of all feed. The development of the ASC Feed Standard has been a long and thorough process because this is an area of great importance to ASC’s overall mission to improve standards in aquaculture. As well as the consultations mentioned above, pilot assessments against the Standard have taken place and these will inform guidance documents for feed mills and producers. In addition, the Standard has been informed by a number of white papers – with documents covering science and findings regarding plant, marine, animal, and micro ingredients. All of these white papers and more can be found on the ASC website. As with all ASC standards, the aim with feed is to work with the industry, rewarding those producers and feed mills that are taking responsible production and sourcing seriously – and helping those that want to make improvements. Aquafeed has always been vital to the aquaculture industry. The new ASC Feed Standard recognizes that it will also be vital to ensuring the industry continues to grow in environmentally and socially responsible ways.

More information: Michiel Fransen Head of Standards & Science ASC E: michiel.fransen@asc-aqua.org

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Hydroxy-selenomethionine reduces the effects of stress in fish Waldo G. Nuez-Ortin, Michele de Marco, AurĂŠlie Moal, ADISSEO Currently, aquaculture production applies conditions that are sub-optimal to the physiological condition of the species. High-stocking densities, poor water quality or fluctuations in water temperature lead to an excessive production of prooxidant molecules that can surpass the capacity of the antioxidant mechanisms of the animal. Furthermore, genetic selection aims for growth at the maximum rates which diverts resources away from self-maintenance processes such as antioxidant protection and is associated with excessive prooxidants production. Therefore, maintaining balance in the animalâ&#x20AC;&#x2122;s antioxidant system must be a priority for nutritionists.

Selenium plays a very important role in antioxidant defence, with the organic forms being the most effective. Recently published trials have shown that providing organic selenium in the form of hydroxyselenomethionine (OH-SeMet) to fish increased selenium deposition in tissues and transfer of selenoproteins to progeny. This translates into improved antioxidant capacity and ability to cope with stress. It was also found that supplementation with OHSeMet reduces lipid peroxidation in muscle, potentially increasing shelf life of fillet. Researchers concluded that supplying selenium as OH-SeMet was advantageous in ensuring optimal performance and quality traits.

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stress, if the antioxidant system is not sufficiently developed, performance and health will be negatively affected.

The benefits of OH-SeMet form is everything SelisseoÂŽ (Adisseo France SAS) contains 100% selenium in the form of hydroxyselenomethionine (OH-SeMet) â&#x20AC;&#x201C; a pure and highly available form of organic selenium. As a compound that has been created by chemical synthesis, its consistency and reliability are assured. The product can withstand the high temperatures and pressures associated with the extrusion processes for aquafeed production. Figure 1. A) Selenium deposition and MDA levels in muscle. Supplemented selenium in ppm. OH-SeMet has been shown B) Relative gene expression of GPx in liver. to be highly effective at What is oxidative stress? increasing selenium deposition At the cellular level, stress increases cellular respiration in tissues, building a reserve of selenium that helps the and production of prooxidants, the so-called reactive aqua species to better cope with stressful conditions oxygen species (ROS). This may lead to excessive that increase the antioxidant requirements. ROS production and an imbalance between prooxidants OH-SeMet enhances protection and antioxidants that result in damaged cell structures. from oxidative stress in muscle Oxidative damage constrains the immune response A trial carried out at the University of Las Palmas and negatively impacts animal performance and (ECOAQUA-IU, Spain) (Marwa et al., 2019) evaluated fillet quality. the effect of different selenium sources and levels on Selenium - a key player in antioxidant defence gilthead sea bream. The peer-reviewed manuscript Selenium is present in protein rich tissues as showed increased selenium deposition with increasing selenomethionine (SeMet) substituting methionine, dietary levels. At 0.5 ppm supplementation, deposition or as selenocysteine (SeCys) as a key part of was 80% higher for OH-SeMet than for sodium selenite selenoproteins. About half of these SeCys containing (Fig. 1A), indicating enhanced protection against proteins are antioxidant enzymes that detoxify oxidative stress in fish muscle. ROS, with two of them being glutathione peroxidase Lipid peroxidation can be measured by the (GPx) and thioredoxin reductases. Supplementing concentration of malondialdehyde (MDA). aquafeed with an optimal level and source of selenium Any reduction of lipid peroxidation in muscle largely contributes to the activity of these antioxidant potentially improves the shelf life and quality of fish enzymes and maintenance of the redox balance. fillets. In this study, a negative correlation between Under production conditions that induce oxidative muscle selenium content and lipid peroxidation

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Enhanced selenium deposition was also observed in the progeny, oocytes and swim-up fry (Fig. 2A), and this translated into enhanced expression of GPx genes and GPx enzyme activity (Fig. 2B). It was concluded that the parental transfer of selenium was more efficient in the form of OH-SeMet, and indicated an enhanced antioxidant capacity of the progeny to respond to stressful events during early life stages.

Figure 2. A) Total selenium in oocytes and swim up fry. B) Enzyme activity of total GPx in swim-up fry.

(R2=0.781) was found, with OH-SeMet leading to a significant reduction of MDA in muscle (Fig. 1A) and in liver. The expression of antioxidant enzymes such as glutathione peroxidase was also evaluated. Increasing OH-SeMet supplementation resulted in higher up-regulation as compared with sodium selenite (Fig. 1B). This further corroborates the enhanced antioxidant protection in juveniles against stress.

OH-SeMet improves the reproductive performance and antioxidant status of the progeny The effect of dietary selenium on reproductive performance, selenium transfer and antioxidant status, was studied in rainbow trout at INRA (France) (Wischhusen et al., 2019). Over a six-month period prior to spawning, broodstocks were fed one of three diets containing a basal level of selenium (0.3 ppm), or a supplemented level of 0.3 ppm either as OH-SeMet or sodium selenite. Results showed significantly higher number of spawnings in broodstock supplemented with OH-SeMet along with a high survival of progeny from fertilization to swim-up fry. Enhanced deposition of selenium in muscle and liver was found in females supplemented with OH-SeMet, thus reinforcing the antioxidant defence mechanisms to better cope with the stress associated to spawning.

Ensured performance under challenging conditions These new peer-reviewed studies add scientific weight to the benefits of selenium supplemented in the form of OH-SeMet. A clear improvement in muscle selenium deposition and consequently in GPx antioxidant activity has been demonstrated. Improved antioxidant capacity translates into reduced lipid peroxidation and potentially into extended shelf life of fish fillets, improved reproductive performance, and overall into better ability to deal with stressful conditions such as those derived current production conditions. References: Wischhusen et al., 2019. Aquaculture 507, 126-138 Marwa et al., 2019. Aquaculture 507, 251-259

More information: Waldo G. Nues-Ortin Lead Scientist Aquaculture ADISSEO, Belgium E: waldo.nuezortin@adisseo.com

Michele de Marco Global Scientific & Technical Manager SelisseoÂŽ ADISSEO, Belgium E: michele.demarco@adisseo.com

AurĂŠlie Moal Global Marketing Manager Health By Nutrition ADISSEO, Belgium E: aurelie.moal@adisseo.com

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Investigate formimino-glutamate (FIGLU) as a potential metabolic marker of nutritional stress Fabio Casu, Aaron Watson, Justin Yost, T. Gibson Gaylord, Daniel W. Bearden, Michael R. Denson The Soy Aquaculture Alliance provides the latest results of their broad research on the utilization of U.S. soybeans in the diets of fish and shrimp. The purpose of this study is to determine if the metabolite formimino-glutamate (FIGLU) is a marker of nutritional stress in fish diets. The overall goal is to improve the metabolic fingerprint of juvenile red drum based on comparison with the two best performing reference diets.

Study design A 12-week feeding trial on young red drum was conducted to investigate FIGLU as a potential metabolic marker of nutritional stress in fish fed diets of 60% or more soybean meal (SBM) as the protein source in fishmealfree feeds. Prior to the 12-week trial, a 7-week “pre-trial” was held in which fish were fed a complete fishmeal control diet. Each fish, averaging 61.3 grams, was sorted into 24 experimental aquaculture system tanks with a temperature of 25° C at the Hollings Marine Laboratory in Charleston, SC. Each of the 24 tanks had 25 fish. During the course of the 12-week study, a total of eight different diets were evaluated:

1. Fishmeal control 2. S upplemented soybean meal (contain 2x methionine, but also supplemented with lysine, threonine and 0.5% (w/w) taurine 3. Unsupplemented soybean meal 4. Folate, 5x general folate requirements 5. Methionine, 2x general methionine requirements 6. Vitamin B12, 5x general vitamin B12 requirements 7. 5x B12, 5x folate & 2x methionine combination 8. Natural reference diet (cut squid, shrimp, fish) Throughout the 12-week study, liver, intestine, heart and muscle tissue samples were taken, as well as plasma. Samples were collected pre-trial, at week zero, week six and at week twelve. While several tissues were sampled, nuclear magnetic resonance (NMR)-based metabolomic analysis focused on the liver tissue samples.

Results Over the course of a 12-week feed trial, experimental 60% SBM diets performed as well as, or better than, a fishmeal control diet. All diets feed

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conversion ratios were 1.0 or below, proving that all the diets performed well. No significant differences were detected in performance recorded among the soy-based diets, despite supplementation (Table 1). The natural reference diet outperformed all experimental feeds. FIGLU was not detected by NMR in fish fed the natural diet but it was detected in all soy-based diets and in the liver of fish fed the fishmeal-based experimental diet which contacted 41% wheat flour. FIGLU is not only a marker of soybean meal consumption, but appears in other diets as well.

Next steps Overall, over the course of the 12-weeks, lower FIGLU levels were found in the vest performing diets (natural diet and 60% SBM diet 2), supporting the hypothesis that higher FIGLU levels indicate a nutritional deficiency. If proposed supplementations prove to significantly reduce FIGLU levels to improve the metabolic fingerprint, new supplementation protocols can be developed and adopted by fish nutritionists to produce alternative

feeds. It would be interesting to investigate this biomarker in other fish species to determine its general applicability.

Key takeaways Fish fed supplemented soybean meal diets of 60% had nearly the same growth, weight and feed conversion of fish fed natural reference (squid, shrimp and fish)

diets. Assessing this biological marker will allow nutritionists to develop feed alternatives within acceptable limits for fish species without causing nutritional stress.

Reference NMR Metabolomics Investigation of FIGLU as a Biomarker of Nutritional Stress in Red Drum (Sciaenops ocellatus) Fed Soy-

The Soy Aquaculture Alliance (SAA) works to create new opportunities for soybean farmers within a growing domestic market: aquaculture. SAA funds programs and research that increases the utilization of U.S. soybeans in the diets of fish and shrimp through affiliations with academic and private researchers and industry leaders. SAA is governed by a volunteer board representing U.S. soybean farmers and industry members. Membership is open to Qualified State Soybean Boards and public and private entities in the soy, aquaculture and seafood industries. To learn more about SAA-funded research projects or becoming a member, visit www.soyaquaalliance.com.

Based Diets, South Carolina Department of Natural Resources, Dr. Fabio Casu, Dr. Aaron Watson, Justin Yost,Dr. T. Gibson Gaylord (USFWS), Dr. Daniel W. Bearden (NIST ret.) and Dr. Michael R. Denson. Full research brief and technical bulletin on file at www.soyaquaalliance.com. Research funded with soybean checkoff dollars. More information: Andy Tauer Executive Director Soy Aquaculture Alliance, USA E: atauer@soyaquaalliance.com

Moving beyond feed In 2020 Hatcheryfeed relaunches as HATCHERY Feed & Management Why

What

To provide high quality editorial and truly

Systems, feeders, genetics, eggs, feed and nutrition, health and hygiene ... and more. All the topics important to hatchery managers and buyers.

international coverage worthy of the professional aquaculture hatchery value chain.

Contact: editor@hatcheryfeed.com

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

EURASTiP, bridging the gap between Europe and Southeast Asia Lucía Barreiro The European Union Vietnam Free Trade Agreement (EVFTA) was signed on June 30 in Hanoi, paving the way for its conclusion and increased trade with the EU and Vietnam. The EVFTA is an ambitious pact eliminating almost 99 percent of custom duties between the EU and Vietnam. Thanks to the agreement, 71 percent of duties will be eliminated on Vietnam exports to the EU, including aquaculture products and a 20 percent more is expected in exports in 2020. In the frame of the new EVFTA, a “honey moon” period for aquaculture in Vietnam is expected as Mathieu Penot, EU delegation to Vietnam, stated at the EURASTiP Brokerage event that was held in Ho Chi Minh City, Vietnam on August 30. EURASTiP aims at launching a European-Asian aquaculture multi-stakeholder platform which will provide a new mechanism to create and reinforce international cooperation on sustainable aquaculture between Europe and Southeast Asia. The majority (70-75%) of seafood consumed in the EU is imported from this region. The Asian aquaculture industry is rapidly growing and faces

serious challenges in terms of sustainability and suitable technologies. In this context projects like EURASTiP are crucial in supporting the industry. The second EURASTiP brokerage event connected European aquaculture stakeholders with Southeast Asian partners through brokerage sessions and field trips in Vietnam and Thailand.

Vietnam, the Asian miracle Whether through extensive, organic or intensive systems, Vietnam has made massive investments in technology and infrastructure. Ten years ago, the aquaculture industry was composed of small stakeholders but now big companies are the largest world suppliers of species including pangasius. The EU import value of pangasius decreased from €331 million in 2013 to €245 million in 2017, a loss of more than 25% which is mainly attributed to the negative perception of the product among certain buyers and consumers. Companies like Vinh Hoan, the largest pangasius producer and supplier to the world market, has enforced its quality control system and has

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Figure 1. Viet-Uc, the largest shrimp hatchery in Vietnam.

made a huge effort to reach the EU standards. In fact, Vietnam is the third ASC certified country in the world after the salmon industry. Certification was identified as one of the main needs of the Vietnamese industry to gain trust, but it has its limitations and other models are needed. A good example is Viet-Uc, the largest shrimp hatchery in Vietnam. Viet-Uc produces 15 billion postlarvae annually and is the only hatchery in Vietnam licensed to operate a breeding and genetics program. They apply hatchery management principles through the whole production process in a high-tech, sustainable, greenhouse farm that has applied Australian (NovacqTM) and European (INVE) technologies. On its path to intensification, pelleted feed is another milestone. With a FCR of 1.5 in ponds, pangasius companies like Vin Hoan face environmental challenges but are embracing new technologies to reach European standards such as a new RAS pangasius hatchery to increase survival and quality. Pangasius and shrimp are Vietnamâ&#x20AC;&#x2122;s two major aquaculture products, but the country aims at diversifying marine species and expanding into open waters since the country has a huge geographic potential for aquaculture. The gradually maturing academia will be a key point for these developments. Vietnam is also looking at Europe and its salmon industry as a reference in terms of byproducts. The Australian-supported company, Vietnam Food,

through its extensive R&D portfolio, is developing a wide variety of shrimp byproducts with even higher value. Vietnam applies a wide variety of culture techniques, ranging from extensive, to intensive and organic. There are still many things to do in terms of quality, transparency, productivity, sustainability, environmental protection and living standards. This is why the country should take advantage of the EURASTiP project and FTA negotiations to implement a wide range of supporting and trade-related subsidies to reach 6 million tons of aquaculture production as expected in the Vision 2030.

Thailand, the tradition Thailand is not on the same page as Vietnam. The country is one of the most important players in the global seafood trade, but has faced big disease outbreaks in the past which has made them rethink their production systems toward more sustainable and biosecure ones. The Thai industry also moved from extensive to intensive and integrated systems. In a country of great traditions, it took more than 10 years to convince farmers to move to artificial feeds. Now Thailand points at smart farms as its next step and is also looking at the salmon industry as a reference. Since diseases are one of the main challenges that the country is facing, CP announced its intention to migrate all its shrimp production from traditional outdoor ponds to indoor RAS biosecure farms, but small farmers are

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Figure 2. Bangladesh and EU delegations toured LST Farm during brokerage event in Thailand.

also moving towards more biosecure systems. Shrimp farming has immense economic importance for Thailand. Due to the increase in production in neighboring countries and the consequent fall in prices, the country has reoriented its targeted market to premium range and diversifying species such as fish and new crustaceans. Thailand’s main advantage is the institutional support that allows the industry make significant strides. The Petchaburi Coastal Fisheries R&D Center, with its zero-waste farm model, and the monosex Macrobranchium culture at LST Farm, supported by the NSTDA, are great examples of the Thai government’s support. There is also a strong network of public centers supporting farms. The EU is Thailand's third largest trade partner. Negotiations for EU-Thailand FTA were put on hold in 2014 and the generalized scheme of preferences (GSP) was withdrawn in 2015 for products including seafood. Thailand has made huge efforts in environmental issues to reach market standards and they expect to reach an agreement to lift the GSP or a new FTA.

Bangladesh, the under-exploited Bangladesh, the main EU supplier of Black Tiger shrimp, is the third targeted country of the EURASTiP project. A country with traditionally extensive industry, poor water quality and a complete lack

of intern infrastructure demands a wide variety of investments. The country also wants to go into intensive systems and artificial feeds. Bangladesh wants to produce feed in its own feed mills since it is mainly imported from India. Ambitious plans for expansion are expected that could benefit from a stronger win-win interaction with European stakeholders. Alongside the emerging Asian technology and innovation platforms, EURASTiP will continue to promote and foster mutually beneficial events to bring together European and Southeast Asian stakeholders, while encouraging the multi stakeholder platform working methodology. In order to optimize aquaculture production and increase their export market, Southeast Asia requires innovation in technology, husbandry systems, production methods and accreditation to the certification schemes that are prerequisite for the EU market. Across the EU aquaculture value chain, Southeast Asia offers unparalleled opportunities for business development, research, knowledge transfer and closer aquaculture collaboration. More information: eurastip.eu

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EURASTiP is funded by the European Union’s Horizon 2020 research and innovation program under Grant Agreement no. 728030.

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Recent Publications Albert G. Tacon, Ph.D. Aloha. Continuing the theme from the last issue, I have collected some of the most recent publications in 2019 that I think will be of interest. Is a taurine supplement necessary in fishmeal-based feeds for juvenile European sea bass (Dicentrarchus labrax)? Saleh, Norhan E; Wassef, Elham A; Ashry, Ahmed M. (2019). Aquaculture International; Dordrecht (Sep 2019): 1-13. The effect of taurine supplementation of fishmeal-based feeds for juvenile European sea bass (Dicentrarchus labrax) was investigated. Fish (initial weight ca. 5 g) were reared for 90 days in 12 concrete tanks (1 m3), with 50 fish in each tank. Four feeds (44% crude protein (CP) and 17% lipids (L)) containing 0 (control (CTRL)), 0.4 (T4), 0.7 (T7) and 1.0 (T10) % taurine were prepared and were fed to apparent visual satiation to triplicate groups of fish. The effects on fish growth, feed utilization, proximate chemical composition, haematology, immune biomarkers and muscle morphometry were examined. An increase in the dietary taurine incorporation resulted in progressive increases in the growth metrics, with the highest values being observed for fish receiving the T10 feed (weight gain 22 vs 18 g/fish in CTRL; protein productive value 31 vs 28% in CTRL). Taurine addition at all levels significantly increased the fish protein percentage, but the percentage lipid was reduced

significantly in T4 fish only (7.8% compared with 9.4% in CTRL fish). Taurine supplementation resulted in elevated blood lymphocyte and monocyte counts and increased serum phagocytic and lysozyme activities. Taurine addition at 1% (T10 feed), the suggested level to boost growth, altered the dorsal muscle cellularity and myofibril ultrastructure, suggesting enhanced muscle function and firmness in comparison with that of the fish given the CTRL feed. Usage of plant natural products for prevention and control of white feces syndrome (WFS) in Pacific whiteleg shrimp Litopenaeus vannamei farming in India. Pandi Palanikumar; Wahjuningrum, Dinamella; Abinaya, Paramachandran; Mariavincent, Michael Babu; Citarasu, Thavasimuthu. (2019). Aquaculture International; Dordrecht (Aug 2019): 1-13. White feces syndrome (WFS) causes severe economic damages in Litopenaeus vannamei culture by the microsporidian parasite, Enterocytozoon hepatopenaei (EHP), and it affects mainly hepatopancreas leading to digestive and absorptive problems, and finally the shrimp have poor growth and

Dr. Albert Tacon is a Technical Editor at Aquafeed.com and an independent aquaculture feed consultant. E: agjtacon@aquahana.com

immune suppression. By improving the health status of hepatopancreas and digestive systems, the disease may be reduced or controlled by alternative approaches especially treating with herbal active principles. The herbal active characteristics like hepatoprotective activity, antioxidants, appetizers, and digestive and growth promoters highly reduce or control the EHP problems due to the broad diversity of active compounds in herbal products. In the present review, we discussed the use, formulation, and method of application of the herbal extracts like Citrus limon, Allium sativum, Zingiber officinale,

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Borassus flabellifer, and Vigna mungoin Indian L. vannamei culture systems by the farmers against white feces syndrome. Mineral nutrition and bone health in salmonids. Baeverfjord, Grete; P Antony Jesu Prabhu; Fjelldal, Per Gunnar; Albrektsen, Sissel; Hatlen, Bjarne; et al. (2019). Reviews in Aquaculture; Burwood Vol. 11, Iss. 3, (Aug 2019): 740-765. In the recent years, challenges faced in salmonid farming with regard to deformities have helped to improve our knowledge on skeletal biology and development of bone health in salmonids. Different nutritional, genetic and environmental factors are associated with skeletal deformities in salmonids and other fish species. Minerals are a group of essential nutrients having a vital role to play in skeletal development, growth and remodelling. The knowledge generated thus far on the structural and functional importance of minerals in salmonid bone health is largely restricted to phosphorus. A brief account of dietary phosphorus‐related bone deformities encountered in salmonids, critical life stages for the development of bone deformities, recent developments in the understanding of their aetiology and dietary phosphorus levels required to improve bone health are presented. The effect of increased dietary level of phosphorus in reducing bone health disorders under conditions of improved feed conversion efficiency and use of triploids in salmon farming are illustrated with help of metadata analysis from literature. With

regard to the role of other essential minerals (macro‐ and micro‐) impacting bone health in salmonids, data available are extremely limited and hence information on other fish species and mammals is summarized in relation to bone development and incidence of deformities. The need to improve mineral bioavailability, utilization and reduce effluent mineral load is presented in brief with example from Norwegian salmon farming. Refinements in mineral requirement recommendations for salmonids and advanced methodologies for studying aetiology of skeletal anomalies, bone mineral status, skeletal development and deformities are also discussed. Modulation of nutrient utilization, growth, and immunity of Nile tilapia, Oreochromis niloticus: the role of probiotics. Kuebutornye, Felix K A; Abarike, Emmanuel Delwin; Michael Essien Sakyi; Lu, Yishan; Wang, Zhiwen. (2019). Aquaculture International; Dordrecht (Sep 2019): 1-15. The production of Nile tilapia, Oreochromis niloticus, over the last few years has increased due to the adoption of intensive farming technologies. However, the continuous increase in O. niloticus production must be based on sustainable practices. Probiotic use in O. niloticus culture is considered a good alternative in improving growth, feed utilization, immune status, and survival against pathogens which are common problems currently faced in intensive culture systems. Nutrient utilization of fish is one

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

of the criteria that determines the production, profitability, and productivity of the aquaculture industry. However, research on probiotics in aquaculture, especially in O. niloticus culture, is much geared towards immunity and disease resistance while areas of equal importance such as nutrient utilization which translates into good health and growth as well as hepatic indexes which detect tissue damage caused by toxicants are less explored. The present review elucidates the effects of probiotics on nutrient utilization (proteins, lipids, fatty acids, carbohydrates, vitamins, and minerals), growth, immune status, and disease resistance of tilapia. Furthermore, this review tries to point out gaps in existing literature that warrant further investigations and development. Probiotic application for sustainable aquaculture. Mahmoud AO Dawood; Koshio, Shunsuke; Mohamed M Abdel‐ Daim; Hien Van Doan. (2019). Reviews in Aquaculture; Burwood Vol. 11, Iss. 3, (Aug 2019): 907-924. Aquaculture, which constitutes one of the largest food production sectors in the world, is preferably practiced with natural organic products rather than with synthetic chemicals or antibiotics. In addition to the daunting challenge of providing food and livelihood to the exponentially increasing world population, the aquaculture industry is key to ensuring that development is based on environmentally sustainable practices, specifically in the

production of aquafeeds. Terrestrial microorganisms that act as natural defence systems of cultured species have been identified as the main producer for the beneficial bacterial candidates. Probiotics have recently gained popularity as beneficial microbes candidates in cultured organisms to maintain the health condition and well‐being of different aquatic animals. This review aimed to understand the necessity of using probiotics as a sustainable alternative to regulate the growth performance, feed utilization and general health condition for sustainable aquaculture. Also, explanatory discussion about the host microbiota and its ability to produce different probiotic strains and the probiotic functionality to ameliorate the host immunity to provide the interactive effects on the host‐ derived probiotics. By presenting the results obtained from the previous studies about the ability of probiotics to sustain the aquatic animal's performances, this study condensed the current knowledge and information for future research and development of the probiotic application in aquaculture. Macroalgae as a sustainable aquafeed ingredient. Wan, Alex HL; Davies, Simon J; Anna Soler‐Vila; Fitzgerald, Richard; Johnson, Mark P. (2019). Reviews in Aquaculture; Burwood Vol. 11, Iss. 3, (Aug 2019): 458-492 Macroalgae, commonly known as seaweed, offer a novel and added‐value dietary ingredient in formulated diets for fish. Production of biomass can be

achieved without reliance on expensive arable land, as seaweed may be collected from coastal regions or farmed. There are three taxonomic groups represented by the term ‘macroalgae’: Rhodophyta (red), Chlorophyta (green) and Phaeophyta (brown). Like terrestrial plants, nutritional content in macroalgae can vary greatly amongst species, genera, divisions, seasons and locations. Aside from their basic nutritional value, seaweeds contain a number of pigments, defensive and storage compounds, and secondary metabolites that could have beneficial effects on farmed fish. This review appraises the beneficial qualities of these macroalgae compounds and their potential for exploitation in commercial finfish feeds. The current knowledge of the effects of macroalgae inclusion in finfish diets is also addressed. From these >50 fish feeding studies that were analyzed, enhancing trends in fish growth, physiology, stress resistance, immune system and fillet muscle quality were reported. However, only a small fraction of algal species has so far been investigated as potential components in finfish diets, and furthermore, this review has identified a number of knowledge gaps that current research has yet to address. To conclude, an appraisal is made of the possible technologies employed to exploit seaweeds to an industrial level through stablishing the algal meal, enhancing the digestibility and functional food properties. Dietary β-1,3/1,6-glucans improve the effect of a multivalent vaccine

in Atlantic salmon infected with Moritella viscosa or infectious salmon anemia virus. Fernando de O Roberti Filho; Albers Koch, João Fernando; Wallace, Christian; Miguel Costa Leal. (2019). Aquaculture International; Dordrecht (Jul 2019): 1-10. The immunomodulatory properties of β-glucans are well documented for several animal species. However, little is known on their use as enhancers of non-specific and specific responses against Moritella viscosa and infectious salmon anemia (ISA) virus, which are two major pathogens affecting the Atlantic salmon aquaculture industry. The present study assessed the effects of dietary β-1,3/1,6-glucans (MacroGard®) and vaccination on the survival of Atlantic salmon ( Salmo salar) post-smolts challenged with M. viscosa or ISA virus. Dietary supplementation decreased mortality in both unvaccinated (55.4%; RPS end 19.9) and vaccinated (9.3%; RPS end 86.6) M. viscosa-challenged fish compared to the non-supplemented groups (69.1% and 28.3% mortality in unvaccinated and vaccinated fish, respectively; RPS end 59 for vaccinate non-supplemented fish). Similarly, mortality of ISA viruschallenged fish decreased from 87.5% in vaccinated fish without supplementation (RPS end 9.2) to 70.9% in the supplemented and vaccinated group (RPS end 26.4). In summary, these findings show that dietary β-glucans increase Atlantic salmon resistance and improve the protective effect of vaccines against the tested pathogens.

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A palatability enhancer that improves the performance of feed pellets in shrimp aquaculture Sofia Morais and Charles Derby Because shrimp are “slow” and selective feeders with highly developed chemosensory systems and because conventional aquaculture systems have low visibility and high particulate matter, attractants and feeding stimulants are commonly incorporated into feed pellets to make them more quickly identified and more palatable, and thus eaten at a higher rate. Animal products including fishery byproducts are widely used palatants (Gatlin et al., 2007; Naylor et al., 2009: Chamberlain, 2010; Suresh et al., 2011). However, important disadvantages of these types of products may be pointed out, particularly regarding byproducts from low-grade fisheries; these include a high moisture content and variable composition and freshness (potentially high levels of oxidation products and biogenic amines), which can affect the nutritional quality of the feed, particularly as these products are often included at high levels. This can lead to inconsistent or poor results as attractants, and even more as feeding stimulants and growth promoters.

A formulated high intensity palatability enhancer The molecular identities of some of the chemostimulants are known for a variety of aquatic animals (Carr, 1988; Carr et al., 1996; Moelzner and Fink, 2014), and although the list is still incomplete, this knowledge has been successfully used in formulating attractants and feeding stimulants (Nunes et al., 2006; Derby et al., 2018). Similarly, Lucta S.A. (Barcelona, Spain, www.lucta.com) has developed a proprietary palatability enhancer (PE) specifically targeting the palatability and performance of shrimp diets. The product was formulated as a complex and concentrated mixture of yeast extract, hydrolysates

of plant protein, specific amino acids, nucleotides, and other flavoring substances in defined proportions. When incorporated into standard feed pellets at 1 to 1.5 g per kg feed and tested in eight-week growth experiments, the PE increased the growth rate and some other functional parameters, such as the intestinal morphology and hepatopancreas protease activity, in Pacific white shrimp, Litopenaeus vannamei, relative to control diets (Zhu et al., 2019). In the experiments reported here, we examined the effect of PE on food ingestion by L. vannamei, using a laboratory behavioral assay of palatability (Derby et al., 2016, 2018).

Palatability behavioral assay The palatability study included four types of feed pellets. Three of the diets were low palatability experimental diets (formulated and produced by Sparos Lda., Olhão, Portugal), and the fourth was a standard commercially available shrimp feed. The compositions of the three experimental diets are shown in Table 1. These were 2.5 mm pellets containing 7.1 percent crude fat and 34.5 percent crude protein coming from soybean meal, wheat meal, wheat gluten, and poultry as the only animal protein (i.e., no fishmeal was included). Two of the diets differed in the feeding stimulant used – 50 g/kg of krill meal (K) or 3 g/kg of the PE – and the third was the negative control (NC) diet that had no feeding stimulants added. The standard commercial control (CC) diet, with 2.4 mm pellets, contained a minimum of 8 percent crude fat and 40 percent crude protein, including 5 percent squid meal. Palatability assays were performed according to Derby et al., 2016. Juvenile shrimp with an average weight of

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

Table 1. Composition of experimental feeds. aCargill, Spain; b Casa Lanchinha, Portugal; cSavinor UTS, Portugal; dFosfitalia, Italy; e Roquette, France; fSapropeche, France; gHenry Lamotte Oils GmbH, Germany; hLecico GmbH, Germany; iInvivonsa, Portugal; j Seah International, France; kEvonik Nutrition & Care GmbH, Germany; lAjinomoto Eurolysine SAS, France; mCarbogen Amcis B.V., The Netherlands; nAker Biomarine Antarctic A.S, Norway; o Lucta S.A., Spain.

5.25 g were group housed with 15 to 30 shrimps per 80-liter aquarium at a temperature of 24–25oC and salinity of 33–35 ppt. Twelve groups of shrimp were tested with each diet. Each experiment consisted of adding 13 g of pellets to an aquarium and allowing three hours for shrimp to feed, after which the remaining pellets were carefully collected, dried and weighed. Control experiments were also performed to correct for changes in pellet mass unrelated to feeding activity of shrimp, in which the same procedure as above was performed except the aquaria did not contain animals. Palatability values were quantified as the amount of pellets eaten per shrimp in a three-hour assay, calculated as the change in dry mass of pellets, including a correction for the control. Figure 1 shows the data, expressed as mean ± S.E.M. (n = 12 aquaria) for each pellet type. A repeated measure of ANOVA with LSD post-hoc tests (α=0.05) shows that 3 g/kg palatability enhancer was 75 percent more effective than 50 g/kg krill meal as a feeding stimulant and 88 percent more effective than the negative control in enhancing t he palatability of the experimental diet, both significant improvements. Furthermore, the PE flavored experimental pellets were 49 percent more palatable than the commercial diet, also significantly better.

Figure 1. Palatability enhancer improves the palatability of feed pellets for Pacific white shrimp. Letters above the bars indicate groups whose values are significantly different. PE: experimental diet with Lucta´s Palatability Enhancer added at 3 g/kg, K: experimental diet with krill meal added at 50 g/kg, NC: experimental diet with no feeding stimulants added (negative control); CC: commercial control diet. See text for explanation of the palatability test.

In conclusion, our research demonstrates that Lucta’s palatability enhancer is highly effective as a concentrated (high intensity) chemostimulant that increases the ingestion of standard feed pellets by shrimp without the use of animal products. The investigation into new chemoattractive and palatable molecules, particularly from classes not previously known to be effective on shrimp and that may synergize with the palatability enhancer when both are added to feed pellets, could lead to the future development of even more effective feeding enhancers for shrimp aquaculture. References available on request. More information: Sofia Morais Feed Additives Innovation Manager Lucta S.A., Barcelona, Spain E: sofia.morais@lucta.com

Charles Derby Regents’ Professor of Neuroscience and Biology Georgia State University, USA E: cderby@gsu.edu

Aquafeed: Advances in Processing & Formulation Vol 11 Issue 4 2019

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