aviNews, a New International Vision of Poultry

May 2020

A NEW

INTERNATIONAL VISION OF POULTRY

Tuesday, Wednesday & Thursday

8th, 9th & 10th

June

2021

MIAMI

THE LANDMARK FOR POULTRY AND ANIMAL NUTRITION PROFESSIONALS IN LATAM & BRASIL

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A NEW VISION OF INTERNATIONAL POULTRY FARMING!

EDITOR

GRUPO DE COMUNICACIÓN AGRINEWS LLC

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aviNews, the most widely read communication tool in the Spanish-speaking poultry sector presents its international sister, aviNews International! aviNews International was created with the aim of building a reference and dissemination space for specialists from the poultry sector, companies, institutions and international researchers.

Despite the differences that may exist between countries, the poultry industry unites us in the need and a task that involves many people. The progressive improvement of the levels of poultry production, together with the increase in the quality of the products offered to consumers, means that the prestige of poultry products continues to rise, earning them a prominent and deserved place in human nutrition.

The entire poultry sector is involved in improving production at a reasonable price to achieve sustainable profits and continue the business. And this is where rigorous and quality information gains prestige, because if we disseminate information that

makes us better, we will all improve our poultry sector.

During the first half of 2020 we also launched our digital media (web, newsletter and monographics) in English and we invite you to visit our website www.avicultura.info to enjoy technical content offered by world-renowned international specialists. aviNews International begins its journey in the publishing world with its magazine with the participation of international consultants from the worldwide poultry sector who have already been seen in our proposal in Spanish, a specialized, innovative and rigorous media. aviNews International’s main objective is to disseminate the extensive and excellent research and development information from the poultry sector worldwide. We hope that our initiative will be well received, becoming the medium of choice for all actors involved in the poultry sector at an international level.

In this first editorial, we would like to thank all those who are already helping us, collaborating for the divulgation of science.

We hope, dear reader, that you enjoy reading this first issue.

Natalia Bellés +34 664 66 06 05 int@grupoagrinews.com CUSTOMER SUPPORT Mercé Soler EDITORIAL STAFF José Luis Valls Osmayra Cabrera Daniela Morales Maria de los Angeles Gutiérrez Priscila Beck TECHNICAL DIRECTION Dr. Gregorio Rosales, MVZ, MS, PhD., DACPV Ing. Eduardo Cervantes Consultor internacional de procesamiento avícola

Dr. Guillermo Díaz Arango Consultor técnico internacional en gallinas de postura

COLLABORATORS

W

e are proud to present aviNews International, the poultry magazine in English for the international market.

Luis Carrasco +34 605 09 05 13 lc@agrinews.es

Brian Fairchild Mike Czarick Dr. Fábio Pértille Shawn Carlton Juan Carlos López Guillermo Tellez Mark W. Jackwood Natalie K. Armour and Martha PulidoLandínez

info@grupoagrinews.com avicultura.info grupoagrinews.com Revista de distribución gratuita DIRIGIDA A VETERINARIOS Y TÉCNICOS

Depósito Legal Avinews B11597-2013 Images: Noun Project / Freepik/Dreamstime

1 aviNews International May 2020

04

Variable Speed Tunnel Fans Can Result in Dramatic Power Savings

14

Dr. Fábio Pértille

Michael Czarick & Brian Fairchild The University of Georgia College of Agriculture and Environmental Sciences

20

Using Flock Data to Make Better Decisions Shawn Carlton

North America Technical Support — Breeder Specialist

2 aviNews International May 2020

Performance evaluation and stress diagnosis in chickens University of São Paulo, Brasil

25

Problems and solutions at the hatchery Juan Carlos López

University of Tolima, Colombia

36

Understanding heat-stress in layers

45

Guillermo Tellez DVM, MS, Ph.D.

This article is a contribution from Hy-Line International

50

What we know about avian coronavirus infectious bronchitis virus (IBV) in poultry — and how that knowledge relates to the virus causing COVID-19 in humans Mark W. Jackwood, MS, Ph.D. Department of Population Health, Poultry Diagnostic and Research Center, College of Veterinary Medicine, University of Georgia, Athens, USA

Alternatives to Antimicrobial Growth Promoters in Poultry

Department of Poultry Science, University of Arkansas Fayetteville, AR, USA.

57

Gallibacterium anatis – An Emerging Pathogen of Poultry?

Natalie K. Armour & Martha Pulido-Landínez Poultry Research and Diagnostic Laboratory Department of Population Animal Health Mississippi State University

Dr. Gregorio Rosales MVZ, MS, PhD., DACPV Poultry Health Consultant

Ing. Eduardo Cervantes The responsibility for the articles, reports, press releases and communications falls exclusively on the authors. The editor is only responsible for his articles or editorials. Neither the publisher nor the authors assume any responsibility for the damages that may be generated, whatever their nature, as a consequence of the use of the data and information contained in this magazine.

International consultant poultry processing

Dr. Guillermo Díaz Arango

International Zootechnician Consultant in Nutrition and Production of Commercial Layers

3 aviNews International May 2020

VARIABLE SPEED TUNNEL FANS CAN RESULT IN DRAMATIC POWER SAVINGS Brian Fairchild & Mike Czarick Department of Poultry Sciences, University of Georgia

V

ariable frequency drive

broilers

“electronic” fans or tunnel fans can result in dramatic

energy savings.

The amount of electricity used by an exhaust fan is not determined by the size of the motor but rather how fast the fan blades are rotating.

Figure 1. Skov 55” variable speed BlueFan

Figure 2. Traditional 1990’s 48” slant-wall fan.

4 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power Savings

The faster a fan spins, the greater the amount of air moved, and the greater the power consumed.

As a result you can modify both the amount of air moved and the power consumed by a tunnel fan by simply increasing or decreasing

ENERGY USED BY THE FAN

the size of the motor pulley, which would change the speed at which the fan blades rotate.

The fact that power usage increases exponentially with fan speed means that relatively small increases in fan speed can result in very large increases in the amount of power used by a fan.

FAN AIR MOVEMENT Interestingly though the air moving capacity of a fan increases proportionally with fan

400 rpm

20.000 cfm

1.000 W

speed, power usage increases exponentially with fan speed.

broilers

We have a fan that is spinning at 400 rpm (moving 20,000 cfm) using 1,000 watts of power

If fan speed is increased by 20%, the air moving capacity of the fan will increase by roughly 20%.

480 rpm

24.000 cfm

1.730 W

We increase the size of the motor pulley so the fan is spinning at 480 rpm (20% increase)

For example, if you have a fan that moves 20,000 cfm that is rotating at 400 rpm and you increase the fan speed to 480 rpm by installing a larger motor pulley the air moving capacity of the fan will increase 20% increasing it to 24,000 cfm.

+20%

air movement

+73%

electrical consumption

In consequence power usage will not increase 20%, but rather would nearly double to 1,730 watts

480 rpm

24.000 cfm

480 rpm x 20 000 cfm 400 rpm

Producers should not replace their existing fan motor pulleys with larger ones to increase the air moving capacity of their fans.

20% increase 24.000 cfm

5 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power

Though it may be initially less expensive to replace motor pulleys than to install additional fans, the nearly doubling of fan power usage for a 20% increase in air moving capacity/air speed would be far more costly in the long run.

For instance, reducing fan speed by 20% will result in the air moving capacity of the fan in the above example decreasing from 20,000 cfm to 16,000 cfm, but the amount of power used by the fan would be roughly cut in half to 512 watts.

Though increasing fan speed is not typically a wise investment, the converse can result in substantial power savings.

400 rpm

20.000 cfm

1.000 W

We reduced movement by 20% Decrease of consumption by 50%

The greater the reduction in fan speed, the more dramatic the reduction in fan power usage.

512 W

broilers

16.000 cfm

FAN: POWER VS. SPEED

1

2

When operating at full speed the fan uses 1,400 watts of power. When the fan speed is reduced from 550 rpm to 450 rpm, a reduction of approximately 20%, fan power usage is nearly cut in half to 780 watts.

But even more dramatic power savings can be realized by reducing fan speed from 550 rpm to 340 rpm.

3

The 38% reduction in fan speed reduces fan power usage by 65% to only 350 watts...about the same amount of power used by a 1/3 hp - 18” circulation fan.

Potential in W Potencia del ventilador (vatios)

Figure 1 provides an example of how power usage varies with fan speed for a 55”.

Maximum velocity

1.500 1.400 1.300 1.200 1.100 1.000 900 800 700 600 500 400 300 200 100 0

1

2 3

0 0

50 50

100 150 200 250 300 350 400 450 500 550 600 100 150 200 250 300 350 400 450 500 550 600 Velocidad del ventilador (RPM)

Speed ​​in rpm

6 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power Savings

We reduce the speed from 550 rpm to 340 rpm

Figure 2 illustrates the general linear relation between fan speed and air moving capacity

Decreased speed by 38%

550 rpm

29.000 cfm

Pressure 0,10’’

We reduce speed by 20%

350 rpm

14.000 cfm 52% reduction in air movement capacity

22.000 cfm

minus 24% of ar movement capacity

Reducing the fan speed from 550 to 340 rpm, a 38% reduction in speed, decreases the air moving capacity of the fan to approximately 14,000 cfm (52% reduction).

At 550 rpm and a static pressure of 0.10” the 55” fan moves approximately 29,000 cfm. When the speed is reduced by 20%, air moving capacity of the fan decreases to approximately 22,000 cfm (24 % reduction).

The actual reduction in air moving capacity of the fans in this instance is not directly proportional to fan speed because the fan is moving air under a static pressure of 0.10” and not zero.

AIR MOVEMENT CAPACITY VS. FAN SPEED

Air moving capacity 0.10 (cfm)

Pressure 0.10 ’’

broilers

450 rpm

30.000 28.000 26.000 24.000 22.000 20.000 18.000 16.000 14.000 12.000 10.000 8.000 6.000 4.000 2.000

Capacity of air movement reduced by 52%

We reduced speed by 38%

200

250

300

350

400 450 Fan speed (RPM)

500

550

600

Figure 2. Fan air moving capacity vs. Fan speed.

7 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power

Variable speed fan

One important characteristic of a variable speed fan is that as fan speed is reduced, its ability to move air under a high static pressure is significantly reduced.

As a result you could have a case where fan speed is reduced 20% but because it is moving air under a high static pressure situation (i.e. 0.15�), the air moving capacity of the fan could be reduced by 50% or more.

broilers

In fact, if fan speed is reduced too much, a variable speed fan may not even be able to generate enough pressure to open its own shutter.

It is generally recommended that variable speed exhaust fans not operate at less than 60% of their indicated “full� speed.

Though it may be difficult to grasp at first, the fan laws tell us that from a power savings standpoint it is better to operate more fans at lower speed, than fewer fans at high speed.

It is not the number of fans operating that will determine your power bills but the speed at which they are operating.

For instance, operating at full speed three BlueFans will move a total of 87,000 cfm (29,000 cfm @ 0.10 X 3) and consume 4,200 watts (1,400 watts X 3).

But, operating five fans at 375 rpm (68%) will move the same amount of air and only use a total of 2,250 watts of power (450 watts X 5), a saving of nearly 50%!

More fans, but lower power bills.

8 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power Savings

Image 1. 55 “variable speed fan

Image 2. Traditional 48 ”Inclined Wall Fan from the 90s

HOUSE B

6

4

VARIABLE SPEED FANS ORIGINAL FANS

55“

HOUSE CONTROL A 8 INCLINED WALL FANS

48” 2

SIDE WALL EXHAUST FANS

36”

The 40’ x 500’ curtain-sided houses were constructed in the mid 1990’s and were equipped with eight 48” slant wall fans and two 36” side wall exhaust fans.

broilers

Recently a study has begun to examine the use of variable speed tunnel fans to reduce fan operating cost. The study is being conducted on a two-house broiler-breeder farm in Northwest Georgia.

Image 3. Variable speed 55” fans equipped with speed controllers (above fans).

In one of the houses, six 55” variable speed Skov BlueFans were installed and four of the original 48” fans were left in the place for back-up purposes (Image 1).

Each of the fans was equipped with a “speed controller” that allows the speed of the fans to be adjusted between 60 and 100%

Fan operation was controlled through the house’s Choretime C2 environmental controller which sent on/off signals to a Skov “control box” which in turn activated each fan’s speed controller as needed (Image 4).

Image 4. Choretime controller with Skov fan interface (blue box) and power meters (left)

9 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power

The initial speed of each of the six 55” fans (HOUSE B) was set so the fans would move the same amount of air as one of the existing 48” fans (340 rpm or 62%) HOUSE A.

With the following configuration: - HOUSE A operating with 8 fans - HOUSE B operating with 6 fans at 82% The air speed in the scratch area of both houses, the conventional house with all eight fans operating and the test house with the six 55” fans operating at 82%, was approximately 480 ft/min with the air speed on the slats near the side of 300 ft/min.

This was done so that when the controller in HOUSE B with the variable speed fans turned on a “tunnel” fan it moved the same amount of air as the 48” fans in HOUSE A. When the controller asked for a seventh tunnel fan the speed of the six variable speed fans (HOUSE B) was increased to match the air moving capacity of seven 48” fans (395 rpm or 71%) of HOUSE A.

Though the six 55” fans were capable of moving roughly 30% more air when operating at 100%, the environmental controller was set only to allow this in the case of excessive house temperatures.

broilers

Likewise, when the controller asked for an eighth tunnel fan the speed of the variable speed fans (HOUSE B) was increased to match the air moving capacity of eight 48” fans (450 rpm or 82%) of HOUSE A.

It is important to note that the objective of the study was not to increase the air speed in the house with the new fans HOUSE B, but to match the air moving capacity of the existing ventilation system with much more energy efficient fans.

Figure 3 ilustrates total power usage of the tunnel fans as function of the number of fans operating in each house.

Air movement capacity vs. fan speed

Power usage (vatios)

2

8.500 8.000 7.500 7.000 6.500 6.000 5.500 5.000 4.500 4.000 3.500 3.000 2.500 2.000 1.500 1.000 500 0

1 0

HOUSE CONTROL A 48”

HOUSE B Variable 55” 0

1

2

3 4 5 Number of fans operating

Figure 3. Total fan power usage vs. Number of fans operating.

10 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power Savings

6

7

8

HOUSE CONTROL A 8

Inclined Wall Fans

1.000 W FIXED POWER

Initial situation

Each of the eight 48” fans in the control house uses approximately 1,000 watts of power regardless of whether it is first fan or the eighth fan to come on.

48“

0

HOUSE B

HOUSE CONTROL A

6 Fans

6 Variable Speed ​​Fans operate at 68%

1.000 W x 6 = 6.000 W

Situation 7 fans

350 W x 6 = 2.100 W

When the first six variable speed fans are turned on they are set to operate at 68% of full speed to match the air moving capacity of the 48” fans in the adjacent house and as a result will only use roughly 350 watts compared to the 1,000 watts consumed by the 48” fans in the adjacent house (65% reduction in power usage).

1

7 FANS

When the controller calls for a seventh fan, each of the six variable speed fans speed up a little to match the total air moving capacity of seven 48” fans and power usage of each fan increases to 530 watts.

6 Variable Speed ​​Fans

1.000 W x 7 = 7.000 W

Situation 8 fans

530 W x 6 = 3.710 W

8 FANS

6 Variable Speed ​​Fans

1.000 W x 8 =8.000 W

broilers

2 When the controller calls for an eighth fan, the speed of the six fans increases again and power usage of each fan increases to 740 watts.

740 W x 6 = 4.440 W

Though the power usage of each of the variable speed tunnel fans increases as the controller calls for the seventh and eighth tunnel fan, it is important to keep in mind that there are only six fans using 530 and 740 watts, respectively, which results in a significant reduction in total fan power usage.

8 Each of the tunnel fans in both the houses were equipped with a power meter connected to a data logging system set to record power usage every 15 minutes.

HOUSE CONTROL A 48”

6

HOUSE B Variable 55”

4

Figure 4 illustrates the total hourly fan power usage over the first ten days of the recently.

3

We observed a significant reduction in the total energy use of the fan.

5

2 1

ct 30 O

t 29 O c

ct 28 O

t 27 O c

ct 26 O

t 25 O c

ct 24 O

t 23 O c

ct 22 O

t 21 O c

t

0

20 O c

Total fan hourly power usage (kw*hrs)

7

Figure 4. Hourly fan power usage.

11 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power

Figure 5 illustrates the daily cost of operating the fans in each of the houses assuming a power cost of $0.10 Kw*hr. As expected, the variable speed tunnel fans reduced fan power usage between 46% and 65% depending on the number of fans operating over the course of the day.

broilers

Though we are at the very beginning of the year long study, this initial window into the potential power savings in using variable speed fans does illustrate why there is increasing interest in this concept.

9$ 8$

Daily fan power cost

7$

Daily cost per fan at 0.10 KW * H

6$ 5$

HOUSE B Variable 55�

HOUSE CONTROL A 48�

4$ 3$ 2$ 1$

Figure 5. Daily fan power cost @ $0.10 per Kw*hr.

12 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power Savings

ct 30 O

ct 29 O

ct 28 O

ct 27 O

ct 26 O

ct 25 O

ct 24 O

ct 23 O

t 22 O c

ct 21 O

20 O

ct

0$

Variable speed tunnel fans, a guarantee for the future Due to the potential for significant power savings there is little doubt that in the future poultry houses will use variable speed tunnel fans.

But before they become commonplace there are a number of questions that must first be answered:

Optimal number of variable speed fans What is the optimal number of variable speed fans to install? When variable speed fans operate at full speed they tend to be not that much

Currently variable speed fans and associated controls are two to

more energy efficient than many fixed speed fans.

three times more expensive than

The key to saving energy is installing

traditional fixed speed fans.

enough fans. The more fans installed,

Longevity/Reliability Variable speed fans require

broilers

Economics

the fewer hours they will operate at 100%, the greater the power savings, but the higher the initial cost.

electronic speed controllers which if they fail makes it essentially impossible to operate the fan.

Power savings Power savings compared to modern fans. This current study is examining

Control Currently not all poultry house environmental controllers can be easily modified to properly control large numbers of variable speed fans.

the replacement of old tunnel fans with lower energy efficiency ratings than most modern tunnel fans. Studies need to be conducted comparing the same or similar modern fan with and without variable speed technology.

Power savings compared to modern fans. This current study is examining the replacement of old tunnel fans with lower energy efficiency ratings than most modern tunnel fans. Studies need to be conducted comparing the same or similar modern fan with and without variable speed technology.

Variable Speed Tunnel Fans Can Result in Dramatic Power PDF DOWNLOAD

13 aviNews International May 2020 | Variable Speed Tunnel Fans Can Result in Dramatic Power

PERFORMANCE EVALUATION

& STRESS DIAGNOSIS IN CHICKENS

broilers

Dr. Fábio Pértille Veterinary doctor, Universidade de São Paulo, Higher School of Agriculture “Luiz de Queiroz”

14 aviNews International May 2020 | Performance evaluation and stress diagnosis in chickens

Chickens are an ideal model organism for studies in phylogeny, embryology, medicine, and other various areas of scientific research.

Chicken protein is known for having a low degree of fat, a high degree of unsaturated fatty acids and low levels of sodium and cholesterol, which responds to current

In order to obtain optimal patterns of high quality meat production, great advances have been made in nutrition and management in chickens.

However, a large part of these advances come from the high pressure of selection of animals in genetic improvement programs to obtain optimal rates of: Ready to sell carcass

consumer demand.

Efficiency Growth

broilers

Domestic chicken (Gallus gallus domesticus) is one of the main sources of highquality protein for humans

15 aviNews International May 2020 | Performance evaluation and stress diagnosis in chickens

broilers

Based on genomic information, the use of molecular techniques has been a fundamental tool to understand genes that control characteristics of commercial interest to improve selection strategies within existing breeding programs.

The use of molecular techniques not only contributes to the improvement of selection, but also to the understanding of the evolutionary history of birds and of the genetic and epigenetic mechanisms involved in this evolutionary process and in the genetic diversification of this species.

This understanding is also important in a humanitarian context to improve the needs of animals and their breeding environments, as current models of large-scale production are questioned in relation to animal health and welfare.

16 aviNews International May 2020 | Performance evaluation and stress diagnosis in chickens

Based on this, our research group in Brazil joined forces in collaboration with a research group in Sweden for the optimisation of molecular techniques to identify markers that will help us understand the genes

Second generation sequencing allowed the development of SNP panels to identify their associations with phenotypes of interest.

However, these SNP panels have limited coverage in functionally important genomic regions in experimental populations.

that control performance and well-

Although NGS is powerful enough to detect

being characteristics in chickens.

informative polymorphisms, its high cost makes it impractical to use it in animal genetic improvement, in genomic wide association studies (GWAS) and in the detection of DMR by immunoprecipitation of methylated DNA

In order to understand the molecular

(MeDIPS).

interest, especially in the last decade, highperformance sequencing techniques, also known as second-generation sequencing (NGS, Next Generation Sequencing), emerged.

In this sense, taking into account the demand for the creation of a cost efficient

broilers

Next Generation Sequencing (NGS)

mechanisms governing these features of

method, we performed in silico simulations for the selection of a restriction enzyme (RE), which allowed the sequencing

These methodologies provided

of a reduced fraction of

a wealth of information that was

the bird’s genome in an

used to identify both genetic mutation and epigenetic variations

efficient, economical,

through molecular markers called

and reproducible way

single nucleotide polymorphisms

for the discovery,

(SNPs) and differential methylation

characterisation and validation of SNPs and

regions in DNA (DMR).

methylated regions.

This strategy made it possible to obtain fragments that present integral distribution and enrich regions of micro-chromosomes, Single nucleotide polymorphisms (SNPs) and differential methylation regions in DNA (DMR) may be responsible for functional

which are underrepresented in commercially available genotyping panels.

changes in the chicken genome. They can be located in genome-neutral regions and are fundamental to many genetic activities and processes.

in silico: made by computer

17 aviNews International May 2020 | Performance evaluation and stress diagnosis in chickens

The micro-chromosome regions are rich in

Thus, based on an approach developed in

genes with a high CpG* island content.

Cornell, USA, we made a detailed step-by-

The cytosine (C) of the CpG dinucleotides is susceptible to methylation in animals and can be used as an epigenetic marker.

step description of the complete optimisation of the reproducible protocol based on the reduced sequence of the chicken genome.

Citosina

STUDY

462 From 462 animals genotyped using this protocol, it was possible to identify SNPs associated with performance characteristics in chickens.

broilers

Some of these SNPs had already been described as associated with the same characteristics in other populations, while others revealed new candidate regions.

Details of these genomic regions associated with animal performance were also published as a scientific paper.

The developed methodology also allowed a refinement in the technique of sequencing methylated DNA by immunoprecipitation (MeDIPseq), since our approach using ER showed a pattern of coverage in the genome that makes it unique compared to other approaches.

This profile includes not only an enrichment of different functional regions, but also a high focus on microchromosome regions that are CpG-rich regions and have higher gene density than macro-chromosomes.

This led us to consider the use of this methodology for the development of other studies involving access to methylation profiles of individuals.

This low cost methodology also had the support of researchers from the Federal University of the Amazon via the application of the technique in a species (colossoma macropomu) of Amazonian fish known as Tambaqui.

SNPs: Single Nucleotide Polymorphisms

* CpG Islands: DNA regions where there is a high concentration of phosphate-linked cytosine and guanine pairs

18 aviNews International May 2020 | Performance evaluation and stress diagnosis in chickens

Traditionally, the analysis of differentiated methylated regions (DMR) analyses the entire genome and has a high cost. Our discovery made it possible to reduce the price of the technique by using an ER derived from GBS optimisation*.

CONCLUSION

CpG enriched by restriction enzyme digestion can be used as sentinels for prolonged stress.

In summary, our work resulted in the discovery of genomic regions associated with performance in

We use erythrocyte DNA from birds, since they are cells that are easily accessible to the field and easily isolated in blood tissue, under different rearing conditions (cage vs. open aviary).

chickens and in the measurement of stress in animals by quantifying differentiated methylated regions.

This methodology brings us very close to the development of a definitive tool for the diagnosis of stress in animals

We identified hundreds of differentiated methylated regions.

subjected to different production

broilers

conditions. It also brings us closer to the direct application of these molecular tools in the production

We can access these DMRs in the repository (EMBL-EBI) of the European Nucleotide Archive (ENA) under the access number PRJEB21356

environment.

Performance evaluation and stress diagnosis in chickens * GBS: Genotyping by sequencing

PDF DOWNLOAD

This work had the support of CAPES (Coordination for the Improvement of Higher Level Personnel – Brazil) and currently its continuity is supported by FAPESP (Foundation for Amparo to Research of the State of So Paulo) References will be provided upon request

19 aviNews International May 2020 | Performance evaluation and stress diagnosis in chickens

USING FLOCK DATA TO MAKE BETTER

DECISIONS

Shawn Carlton North American Technical Support. Reproduction specialist

T breeder

he goal of any broiler breeder program is to produce the

greatest number of hatching eggs per hen housed. A production data analysis can help determine which flocks are meeting their genetic potential and which flocks are not.

When conducting a production data analysis, you want to look at: Body weight curves uniformity Production Female and male mortality throughout the growing phases of the pullets and hens.

Identifying trends in these measurements can help determine which key performance indicators we could be missing to give us the desired results. Comparing your top and bottom flocks can provide insight into why the bottom flocks are underperforming.

Comparing the best and worst flocks can shed light on why “bad� flocks perform worse.

20 aviNews International May 2020 | Using Flock Data to Make Better Decisions

Key areas of focus Achieving standard 4-week body weight to promote flock uniformity.

Preventing female and male body weights from being overweight during the maintenance phase (from 6 to 15 weeks of age).

Females getting the proper turn-up from 16 to 20 weeks of age (this is very important as birds are preparing for the lay phase). Proper turn-up in this phase is 35%.

The success of any breeding program must be based on data.

Example

The success of any breeder program must be driven with data. Decision-making is dependent upon the quality of data and ensuring that the numbers are accurate and complete. This means making sure that everyone within the complex collects data in the same format as variability in how data is collected or tracked can skew results.

For example, when weighing birds, weigh all the houses the same way (ex: weighing three pens in the house to get an accurate average weight, weighing all the birds that are caught to weigh).

Also, it is important to identify and remove outliers from the production data analysis as leaving them in these data points can skew results.

Removing these outliers will give you a more accurate picture of overall flock performance.

Egg Production Producing the greatest number of chicks per hen housed (Chicks/HH) at the lowest cost is the ultimate goal of a broiler breeder management program.

Therefore, looking at egg production is the first step in a production data analysis. Once the top and bottom flocks have been identified, it is easier to see what could be causing the discrepancy.

21 aviNews International May 2020 | Using Flock Data to Make Better Decisions

breeder

Having a smooth transition from the rearing house to the production house.

Goal

Data Collection

Controlling male body weight at move – Males MUST be synchronized with females at move.

There are a number of factors that can be attributed to low egg production Improper or poor lighting – Must have a tenfold increase in intensity from pullet to hen house.

Using the wrong light spectrum – Production birds need the red/ orange spectrum to be stimulated.

When using LED bulbs at 2700 Kelvin rating is recommended.

Poor light placement and spacing in the house.

Inadequate feeder space.

Inadequate water volume or water availability at peak demand times.

It may be difficult to determine which factors may be contributing to low egg production as even a one to two percent difference in mortality can have a big effect on production.

For example, a one percent increase in hen mortality is roughly equal to 1.5 fewer hatching eggs. Therefore, egg production can be greatly affected by seemingly insignificant differences between flocks.

breeder

Too much stress (as a result of vaccinations or moving from the rearing to the laying house).

Lack of nutrients in feed.

Hatchability is another big driver of chicks per hen housed. It is important to manage male weights and fleshing in the hen house.

Not achieving body weight standards.

Body weight (gr) 2404 2291 2177 2064 1950 1837 1724 1610 1383 1270 1157 1043 930 816 8

Body weight in rearing Standard

Top Actual

Bottom Actual

Standard Weight (gr) 16 weeks 1610 Weight 20 weeks 2150 34% % weight gain

16 Age(weeks)

20

22 aviNews International May 2020 | Using Flock Data to Make Better Decisions

Top

Actual 1656 2245 35%

Bottom

Actual 1728 3620 31%

Body Weight Curves and Uniformity

Feed Curves Finally, measuring the feed curves of each flock is the last step to

It is important to make sure that each flock’s body weight curve is matching or close to matching the Cobb standard by the time of light stimulation. Body weights that are too low or too high can negatively affect peak production.

Typically, bottom flocks stall on weights between weeks 16 and 20 if they are heavy in the maintenance phase of rearing, or if they achieve too much body weight gain early in the production house.

conducting a production data analysis.

As feed directly impacts body weights, which directly impacts egg production, this key performance indicator can be the most telling difference between the top- and bottom-performing flocks.

breeder

Other measurements that should be collected in a production data analysis are body weight curves and uniformity.

In general, the feed curve should increase through peak production, at which point it should decrease at about 29 weeks.

It is advisable to increase feed intake during production so that the hens can perform to the best of their abilities during egg production, at which point bottom flocks can actually surpass the top flocks. Thus, it is possible to fix poor-performing flocks, but only if you are keeping track of that data.

23 aviNews International May 2020 | Using Flock Data to Make Better Decisions

Feeding through peak Kg/100 chickens 15.9 15.0 14.1 13.2 12.2 11.3 10.4 9.5 8.6 7.7 20

Higher Average

Lower Average

Nutrient availability Feeding space Water quantity/quality

25 30 Age (weeks)

36

breeder

Factors that can contribute to feed curves Kg/100 chickens 35 34 33 32 31 30 29 28 27 26 25 25

There are many factors that can contribute to feed curves. Amount of feed is typically the most influential, but other factors include:

CONCLUSION

Withdrawing feed after peak Higher Average

35

45 Age (weeks)

At the end of the day, decisions should be made according to data collected at your particular location. When it comes to poultry farming, especially broiler breeding, a small variation can have a dramatic impact on your bottom line.

Lower Average

55

That’s why consistent and accurate recording of data is key to staying on top of which aspects of production need adjustment.

61

Using Flock Data to Make Better Decisions PDF DOWNLOAD

24 aviNews International May 2020 | Using Flock Data to Make Better Decisions

PROBLEMS AND SOLUTIONS AT THE HATCHERY

hatchery

DVM., MVSc., PhD Juan Carlos López Hatchery Specialist. Hendrix-Genetics

O

pening of unhatched eggs remaining on the tray and the assessment of lesions or abnormalities in

the rejected fowls during hatching are a significant tool which allows to evaluate the management and conditions fertile eggs were exposed to during a certain period of time.

Those very trays where embryo diagnosis is performed must be monitored for moisture loss

Mortality occurs during every embryonic

upon transfer, hatching window and weight of the

stage of development. What is important

chick with respect to the initial weight of the egg.

is to be able to establish what is “normal”,

The chances of being able to spot the cause

and in case something is not, to be able

of the problem are increased when the

to determine the cause(s) at that time.

findings upon opening the eggs are related

Embryo diagnoses must be

to the above monitored parameters.

routinely performed, and not only when problems arise.

A few cases found in incubation plants, which can be useful to understand future abnormal embryo mortality in our plants are shown next.

25 aviNews International May 2020 | Problems and solutions at the hatchery

CASE 1 In this case, an abnormal increase of dead embryos was observed in the first two days of incubation, as well as a high percentage of weak shells and an intermediate increase of contamination-related mortality.

Photograph 1. Fertile, dead before incubation

Background Considerable rise in very early embryo mortality (day 1)

hatchery

Photograph 1 and 2 Increase in the percentage of weak white shells and contamination Photograph 2. Dead on day 1-2 of incubation

Photograph 3 Mottled yolks Photograph 4

Photograph 3. Weak shells

Increase in intermediate mortality due to contamination Photograph 5

There were no changes in the way eggs were handled in the farm -collection, spraying, storage temperature, or transportation

26 aviNews International May 2020 | Problems and solutions at the hatchery

Possible Causes Infrequent collection Prolonged and/or inappropriate storage Prolonged pre-incubation Excessive spraying Severe nutritional deficiencies Incorrect transportation Temperature too high or too low during the first days of incubation Lack of egg turning

Photograph 4. Mottled yolks

hatchery

Ocratoxins and T2

Conclusions In this case, early mortality was the result of a severe stress situation (earthquake): mottled yolks (disturbance of the vitelline membrane) were the evidence.

Weak shells, some of them fissured, which lead to contamination, were the result of the stress caused by oviposition before the shell was completed, or an abnormal retention of the egg in the egg formation gland, which resulted in subsequent eggs not having enough time to develop properly.

Photograph 5. Contamination

27 aviNews International May 2020 | Problems and solutions at the hatchery

CASE 2 In this case the existence of an abnormal percentage of red hocks and pipped eggs were observed, as well as the presence of umbilical cords (“navel strings”).

Background Increase in the percentage of chicks with Photograph 6. Red elbows

dehydrated legs and “red hocks” Photograph 6 Eggs laid by pullets in their

hatchery

first few weeks laying.

Normal hatching window.

Water loss upon transfer (8%).

Possible Causes

Eggs remaining on tray show pipping.

Rise in the percentage of chicks having navel strings.

Humidity too high during incubation High temperature during incubation Low temperature during incubation Vitamin deficiency Changes in the makeup of the shell

Photograph 7. umbilical cords

28 aviNews International May 2020 | Problems and solutions at the hatchery

CASE 3 In this case, the existence of a high percentage of chicks with navel issues, such as black buttons, navel strings, and omphalitis.

Photograph 8. Black button navels

Background Increase in the percentage of rejected chicks during hatching due to navel issues.

White feathers and lethargic chicks.

hatchery

Eggs incubated in multiple load machines.

Conclusions In this case the cause was the excessive moisture in the incubator and hatchery. The

Possible Causes

high amount of pipped eggs, along with the presence of umbilical cords confirms the diagnosis Photograph 7 Usually, when the temperature is low the hatching is delayed. A high temperature leads to red elbows, splayed legs and crooked toes, and the hatching window shows an

High humidity in the hatchery High temperature during the last week in incubators and hatchery Low temperature “Omphallitis� contamination

acceleration of embryonic development.

29 aviNews International May 2020 | Problems and solutions at the hatchery

Photograph 9. Onfalitis Signs that must be observed in order to classify umbilical malformations as inflammation (omphalitis).

Hot Blush Swelling Pain Loss of function

hatchery

Conclusions The cause varies depending on the type of lesion.

Black button navels -Photograph 8- are the consequence of a high temperature during incubation.

Starting from the second week the embryo’s temperature measured at the shell was 38.3ºC (100.9ºF) – 38.9 ºC (102ºF).

High temperature affects the thyroid–IGF1-GH hormonal axis, which controls growth and chondrocyte differentiation; it lowers the expression of type X collagen and the transformer growth factor beta, two major proteins involved in ossification.

In addition, high temperature accelerates embryonic developement, thereby demanding a greater consumption of oxygen, which can passively enter through the shell pores; the embryo exchanges energy from the yolk lipid metabolism, which demands oxygen due to the glycogen stored in the embryonic muscles. This process can result in an accumulation of lactic acid and muscle fatigue.

30 aviNews International May 2020 | Problems and solutions at the hatchery

Lack of absorption of the yolk influences the utilization of critical nutrients for the early development and shaping of bones.

Poorly closed navels are generally due to a low incubation temperature. The “navel strings” are due to high humidity in the hatchers, which prevents the blood vessel to naturally dry out and come apart.

Omphallitis should be distinguished from the previously mentioned navel issues. Omphallitis-Photograph 9- is an inflammatory process, resulting from an infection.

The scheme below summarizes how temperature affects bone and tendon formation and causes the yolk sac not to be used correctly, because due to its greater volume, it is unable to completely retract into the abdominal cavity, which causes a portion of it to remain on the outside, becoming what is known as “black button�.

HIGH TEMPERATURE < Affects the thyroid

THYROID HORMONAL AXIS

Type X collagen

Control growth = Chondrocytes

Transforming growth factor

Ossification O

It enters through the pores of the shell

hatchery

2

O2 Demand

Embryonic growth

Muscle glycogen Energy of the embryo muscles

Lactic acid

Metabolism of lipid buds

LACK OF YOLK ABSORPTION USE OF CRITICAL NUTRIENTS

for

Early development Bone formation

31 aviNews International May 2020 | Problems and solutions at the hatchery

CASE 4

Photograph 10. Pipped egg

In this case, a reduced hatchability, pipped eggs, chicks with shells on their feathers, and excess fluff on hatcher doors were observed.

Background Photograph 11. Pipped egg Significant drop in the hatchability due to a significant increase in pipped eggs Photographs 10 and 11 Chicks with shells attached to feathers Photograph 12

hatchery

Excess fluff on hatcher doors.

Photograph 13

Photograph 12. Chick with shell attached to feathers

Possible Causes Prolonged storage Unsuitable temperatures; low within the incubator and high in the hatcher Incorrect ventilation in hatcher No turning Upside down positioning Low humidity in incubator and/or hatcher

Photograph 13. Fluff on hatcher door.

32 aviNews International May 2020 | Problems and solutions at the hatchery

Porous or fissured shells

CASE 5 In this instance we found a high mortality rate in the farm; the chicks had lost their apetite, they were lethargic due to yolk sac issues and chick motricity.

Conclusions In this case, several factors had an impact: Eggs were kept in storage for 18 days.

Background

The temperature within the

A rail for an additional row of eggs was used with a different eggshell conductance and for larger chicks.

The humidity inside the hatcher was too low.

High mortality rate in the first 7 days in the farm.

Death resulted from small chicks with large yolk sacs.

Organs did not have lesions exhibiting bacterial contamination.

Usually, when humidity is too high, we observe wet chicks covered with albumen,

Chicks exhibited a lack of appetite and

or fully developed chicks that donâ&#x20AC;&#x2122;t pip.

lethargy upon their arrival at the farm.

The chick to egg ratio shows a low weight loss.

Photograph 14. High temperature during the last week in the incubator and hatcher.

33 aviNews International May 2020 | Problems and solutions at the hatchery

hatchery

incubator was low.

Possible Causes

Photograph 16. Chick with an 8% yolk sac ratio

High temperature over the last period in the incubator (above 38.3ºC/101.3ºF at the eggshell) and in the hatcher (chicks having rectal temperatures above 40.6 ºC/ 105.08ºF) Chicks subjected to low temperatures during the waiting period at the plant and/or during transportation (rectal temperatures lower than 39.4 ºC/ 102.9ºF)

hatchery

High carbon dioxide levels in the hatcher (over 7,000 ppm) and upon reception at the farm (over 2,500 ppm)

Photograph 15. Chick with a 20% yolk sac ratio

Photograph 17. Upside down chick

34 aviNews International May 2020 | Problems and solutions at the hatchery

Conclusions

The high levels of carbon dioxide and high temperature upon reception can generate “upside down chicks”

In this case, the temperature during the last

Photograph 17

week in the incubator and hatcher was too high Photograph 14

The blood samples from affected chicks show high levels of lactic acid and low

That high temperature affected the absorption

glucose. Glucose is essential for the

of the yolk sac. Chicks with large yolk sacs

brain. Due to the low glucose level the

do not have the need to search for food.

stored glycogen is used, thus generating a great oxygen demand. When there is not enough oxygen available, lactic

In addition, high temperatures affect the

acid is produced, which is extremely

leg bone formation and hence, motricity.

irritating for the chicks’ nervous system.

Photograph 15 shows chicks with a yolk sac

This situation is more frequent in

ratio of 20% in contrast with Photograph

eggs from the first laying week,

16, which shows fowls with 8% yolk sacs.

since the eggshell is thicker, which

hatchery

makes oxygen diffusion difficult.

Problems and solutions at the hatchery

The table below can be used as a guideline for assessing breakouts in broiler chickens (Tullett 2009).

PDF DOWNLOAD

ALTERATIONS IN EMBRYONIC DEVELOPMENT BREEDING AGE WEEKS

INFERTILE

DAY 1

DAY 2

BLOOD RING

BLACK EYE

NAVEL PROBLEMS

INVERTED / MALPOSITION PIPPED AIR CELL PIPPED SHELL

25-30 weeks

6%

1%

2%

2.5 %

1%

1%

1.5 %

1%

31-45 weeks

2.5 %

0.5 %

1%

2%

0.5 %

0.5 %

1%

46-50 weeks

5%

0.5 %

1%

2.5 %

1%

0.5 %

51-60 weeks

8%

0.5 %

1%

3%

1%

0.5 %

BROKEN

CONTAMINATED

1%

0.5 %

0.5 %

1%

0.5 %

0.5 %

0.5 %

1%

1%

0.5 %

0.5 %

0.5 %

1.5 %

1%

0.5 %

1%

1%

Table 1. Alterations in the hatchable egg and embryo development as a function of breeder age.

35 aviNews International May 2020 | Problems and solutions at the hatchery

UNDERSTANDING

HEAT-STRESS IN LAYERS PART 1

layers

MANAGEMENT TIPS TO IMPROVE FLOCK PERFORMANCE IN WARM WEATHERS

High temperature periods often generate a high relative humidity. This usually happens during the summer months.

Heat stress can deeply affect the productivity of a flock.

At ambient temperatures of over 33° C (91.4 °F), high mortality and great loss of production are apparent, though at less extreme temperatures we often overlook heat stress as a cause for poor growth or loss of egg production, as well as a lower eggshell quality.

36 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

Thermoregulation in poultry The excess body heat is removed via four different mechanisms: Convection Loss of body heat through cold circulating air. Fowls enlarge the exposed surface area by lowering and extending their wings away from their bodies. Convection is aided by air movement, thus creating a cold air effect

Convection

Vasodilation Blood swells wattles and combs, sending the core body heat to the surface, which is then lost to the surrounding air.

layers

Radiation Electromagnetic waves transfer heat via the air to a distant object. Body heat is irradiated to colder objects in the barn (for example, the walls, the ceiling, or the equipment).

Radiation

Evaporative cooling Fast, shallow breathing with mouth open increases loss of body heat by increasing evaporation of water in the mouth and the respiratory tract. Decrease of moisture in the air contributes to evaporative cooling.

Conduction

Evaporative cooling

Loss of body heat to colder objects in direct contact with fowls (for example, the litter, roost floor, cage wire).

Fowls look for the coolest areas in the shed. Fowls lie on the floor or dig into the litter to find a cooler place.

Conduction

Figure 1. Bird mechanisms to remove heat.

37 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

Radiation, convection, and conduction together are known as sensible heat loss

At temperatures higher than the thermoneutral zone,

The thermoneutral zone in the fowl is generally

from growth and egg production, resulting in a lower yield.

between 18– 25°C. Within this temperature range, loss of sensible heat is suitable to maintain the

the fowl uses its energy to maintain a normal body temperature and its metabolic activities. This takes energy

At high ambient temperatures, fowls start breathing

normal temperature of the fowl at 41°C.

with mouth open in a fast, shallow manner known

Above the thermoneutral zone, the efficiency of sensible

from the respiratory tract. When panting fails to

heat loss mechanisms is diminished. At this point, water

maintain the body temperature, the fowl becomes

evaporation from the respiratory tract becomes the main

lethargic, comatose, and can even die.

heat loss mechanism in the fowl. The evaporation of one gram of water dissipates 450 calories of body heat.

as gular reflux, to increase water evaporation

The broods that have not been previously acclimated to high temperatures usually suffer the greatest productivity losses and mortality.

EFFECTS OF HEAT STRESS

Younger fowls who have been exposed to high ambient temperatures are thermically more tolerant later on in life, due to the production of heat shock proteins.

layers

FOOD CONSUMPTION EGG PRODUCTION EGG WEIGHT

LOSS OF PRODUCTION OCCURING DUE TO HEAT STRESS

SHELL QUALITY ALBUMEN HEIGHT

THE MAXIMUM TEMPERATURE THE FLOCK HAS BEEN EXPOSED TO

GROWTH DURATION OF HIGH TEMPERATURES MORTALITY (especially with acute heat stress)

CANNIBALISM INMUNOSUPPRESSION BIRTHS ROOSTER FERTILITY

38 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

TEMPERATURE CHANGE RATIO RELATIVE AIR HUMIDITY

HEAT AND HUMIDITY STRESS INDEX FOR COMMERCIAL LAYERS (Temperature stress index = 0.6 x dry temperature + 0.4 x wet temperature)

ºF

ºC

68 72

5

10

15

20

25

30

35

40

45

20

63

63

63

64

64

64

64

65

22

64

65

65

66

66

66

67

67

75

24

66

67

67

68

68

69

69

79

26

68

69

69

70

70

71

82

28

70

70

71

72

72

86

30

71

72

73

74

90

32

73

74

75

93

34

75

76

97

36

77

78

100

38

78

79

50

55

60

65

70

75

80

85

90

95

100

65

65

66

66

66

66

67

67

67

67

68

68

67

68

68

69

69

69

70

70

70

71

71

72

70

70

70

71

71

72

72

73

73

74

74

75

75

71

72

73

73

74

74

75

75

76

77

77

78

78

79

73

74

74

75

76

76

77

78

78

79

80

80

81

82

82

74

75

76

77

78

78

79

80

81

81

82

83

84

84

85

86

76

77

77

78

79

80

81

82

83

84

84

85

86

87

88

89

90

77

78

79

80

81

82

83

84

84

85

86

87

88

89

90

91

92

93

79

80

81

82

83

84

85

86

87

88

89

90

91

93

94

95

96

97

81

82

83

84

85

86

88

89

90

91

92

93

95

96

97

98

99

100

layers

Temperature

Relative humidity (%)

Figure 2. Adaptation of heat stress index combining the effects of temperature and humidity for layers. Xin, Hongwei, and Harmon, Jay D., “Livestock Industry Facilities and Environment: Heat Stress Indices for Livestock” (1998) Agriculture and Environment Extension Publications. Book 163, Iowa State University

Danger (heat index 76-81) Heat stress conditions are present; take immediate action to reduce heat stress in the Flock; increase ventilation in closed barns and use relative humidity- based evaporation pads; in open sheds, turn on fans and misters. Adjust nutrient density in the diet to make up for any drop in food consumption. Move the air over the fowls at a maximum speed of 1.8–2.0 meters per second. Periodically purge water lines with cold water.

Closely monitor the brood behavior. Maximize cooling at night.

Fowl’s Comfort Zone (heat index <70) No action is required; it is the right time to prepare for a future warm season.

Alera (heat index 70–75) Start taking action to reduce heat stress in the brood; increase ventilation; increase fan speed and use misters (misters can work based on the relative humidity).

Monitor the fowls’ behavior for any sign of heat stress; make sure drinker and ventilation systems are working right.

Emergency (heat index > 81) Extreme heat stress conditions are present; avoid handling fowls for transport and vaccination. Do not feed them during hot hours of the day. Lower light intensity to reduce activity and heat generation in the fowls.

When temperatures are high, fowls start to breathe in a fast and shallow manner, with mouth open

39 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

Ambient temperature to relative humidity Ratio

The effective temperature is obtained through the combination of air temperature and relative humidity. Depending on how these parameters are inter-related, a heat stress condition can arise.

Effective temperature

A rise of moisture in the air at any temperature will increase discomfort and heat stress in the chicken.

layers

Stress

Temperature and relative humidity

Figure 3. The effect of the temperature and relative humidity of the air on the bird is the effective temperature.

Farmers must closely monitor the temperature and humidity in their facilities.

Generally, during the day, the temperature rises and relative humidity drops. The best cooling method during low humidity periods is by evaporative cooling (mister, sprayer, or moist pad).

In the afternoon, when temperature drops, and humidity typically rises, the use of misters to enhance humidity can increase heat stress.

When humidity is high, use only fans to speed up air circulation and reduce heat stress in open sided barns.

Air movement creates a cold air effect, and the body senses a temperature drop due to the air Flow. A heat stress index table has been developed for commercial layers.

(Figure 2)

Flocks that have not been previously acclimated to high temperatures are the ones with the greatest loss of productivity and mortality Figure 4. You have to take into account the time of day, and whether the temperature and humidity increase or decrease, to decide whether to use fogging or just the fans.

40 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

Effect of heat stress on the eggshell quality

The flocks of layers under heat stress often lay eggs

Another contributing factor to thin eggshell is the

having thinner and weaker eggshells due to an acid/

decrease in calcium consumption as a result of reducing

base disturbance which takes place in the blood as a

food consumption and escalating loss of phosphorus.

result of panting (hyperventilation, gular reflux).

When birds hyperventilate to shed body heat, there is an excessive loss of CO2 gas in the lungs and blood. Decrease of CO2 gas in the blood causes the blood pH to rise or become more alkaline. This

Increasing the level of blood pH decreases the

Potassium chloride, ammonium chloride,

activity of the enzyme carbonic anhydrase, which

or sodium bicarbonate (2â&#x20AC;&#x201C;3 kg/MT of

results in a reduction of calcium and carbonate ions

feed) can replace the lost electrolytes

transferred from the blood to the Shell gland (uterus).

during heat stress and promote water

Increasing diet calcium will not correct this problem.

consumption. It has been shown that these

layers

RESTORING THE ACID/BASE BALANCE

condition is known as respiratory alkalosis.

treatments are useful to reduce mortality in flocks affected by acute heat stress.

Lungs CO2 + H2O

Blood H2CO3

HCO3- + H+

Consecuences

Non-diffusible calcium bound to proteins

Shell gland CO3- + H+ Ionized diffusible calcium

Hyperventilation causes

As a result, the pH in the blood

Decreased calcium and

an increase in the loss of

increases, producing a respiratory

carbonate secretion by

CO2 gas in the lungs.

alkalosis; This decreases the

the shell gland results in

activity of carbonic anhydrase

thin and weak shells.

(an important enzyme for the formation of the eggshell).

Figure 5. Demonstration of disruption of acid / base balance caused by heat stress.

41 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

Management of the drinker system for a flock affected by heat stress During high ambient temperature times, the flock has high water consumption requirements. The water – food consumption ratio is normally from

Keeping water at a temperature below 25°C helps maintain a greater water consumption, thus causing a greater feed consumption.

2:1 at 21°C, but it is increased to 8:1 at 38°C. A water temperature above 30°C will have a negative impact on water consumption, and it will also adversely affect feed consumption.

For flocks affected by heat stress there must be as much available drinking water as needed.

layers

Make sure drinkers have a suitable water flow (> 70 ml/minute/ nipple drinker).

Make sure drinkers work correctly and provide enough space.

For flocks bred on the floor, providing additional drinkers might help balance the water consumption increase.

Use vitamins and electrolyte supplements in drinking water to compensate the loss of sodium, chloride, potassium, and bicarbonate in urine.

Supplementary electrolytes work best when they are used before a sudden rise of ambient temperature.

Drinking water is heated when tanks are directly exposed to sunlight

Such tanks must be light colored, be insulated, and be covered to avoid direct exposure to sunlight. Ideal water tanks are those placed within the barns, or those installed underground.

Fresh water can help reduce the birds’ core temperature, and hence reduce the impact of heat stress.

Purging water lines in the afternoon helps cool water down and this has been shown to enhance feed consumption and sustain egg production in a lot of layers affected by heat stress.

Plastic lines are quickly heated by ambient temperature, making it difficult to cool water below the air temperature, particularly near the ends of long water lines.

Heat stress-affected layer flocks lay eggs with thinner and weaker eggshells due to the blood acid/base balance disturbance as a result of panting

42 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

Management of a flock affected by heat stress Do not disturb the chickens during the hottest hours of the day or early evening). Adapt work schedules and lighting schedules such that the routine chores are performed early morning or at night.

Management practices which require handling the fowls, such as beak trimming, transport, and vaccinations (via a drop into the eye, the wing surface, or

Caged in birds are more susceptible to heat stress because they are unable to look for a cooler area, and inside the cages they have a lesser chance of shedding heat by conduction. The temperature inside the cage can be much higher than the ambient temperature measured along the aisles. An increase of air speed among cages enhances los of heat by conduction and removes the air entrapped among the birds.

by injection), should not be performed early morning.

Do not work feeders during the hottest time of day.

Use misters and vaporizers to enhance evaporative cooling during the day. Turn on the misters for 2 minutes every 10 minutes. Misting schedules must be adjusted based on the temperature and humidity within the barn.

Using ceiling sprayers during extremely high temperatures can remove heat from the ceiling and cool the barn inside.

Transport birds early morning or at night.

Place fewer birds in each carrier case and keep empty cases in the truck to make room for

layers

Misting at the air inlets of negative pressure ventilation systems has a suitable cooling effect.

Avoid having too many cages; cages containing too many birds prevent air from flowing among the birds, thus diminishing the performance of ventilation and increasing the heat load in the barn.

ventilation around the birds during transport.

Adjust thermostats such that fans work throughout the night and early morning. The purpose of this is maximizing the cooling inside the barn during the night and prolong the mild temperature period until the next morning.

Increase air circulation in open barns by means of fans. Assure a speed of 1.8â&#x20AC;&#x201C;2.0 meters/second where the chickens are.

43 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

Temp. environmental (°C)

Air Movement (m3 / hour per 1000 birds) 1 week

3 week

6 week

12 week

18 week

19+ week

W-36

HLB

W-36

HLB

W-36

HLB

W-36

HLB

W-36

HLB

W-36

HLB

32

340

360

510

540

1020

1250

2550

3000

5950

7140

4650–9350

9340–12000

21

170

180

255

270

510

630

1275

1500

2550

3050

4250–5100

5100–6800

19

120

130

170

180

340

420

680

800

1870

2240

2550–3400

3060–4250

layers

Figure 6. Recommended ventilation ratio for commercial layers (W-36 and Hy-Line Brown). For more information, see the Hy-Line International management guides. Acknowledgments: To Dr. Hongwei Xin, Professor, Department of Agriculture and Biosystem Engineering and Department of Animal Sciences, Iowa State University, Ames, Iowa, USA.

Understanding Heat-stress in Layers (Part I) PDF DOWNLOAD

44 aviNews International May 2020 | Understanding heat-stress in layers (Part I)

ALTERNATIVES

TO ANTIMICROBIAL GROWTH PROMOTERS IN POULTRY Guillermo Tellez DVM, MS, Ph.D. Department of Poultry Sciences, University of Arkansas Fayetteville, AR, USA

S

It has been estimated that foodborne infections in the USA cause over seventy-six million illnesses responsible for five thousand

Elimination of enteric pathogens from animal products intended for human consumption has become a priority due to the increase in the number of cases of toxic infections produced and in accordance with government regulations.

In addition, the annual economic loss attributed to the four most common enteropathogens (Salmonella spp., Campylobacter spp., E. coli and Shigella spp.) has been estimated to reach $ 7 billion dollars.

As a result, several methods to control foodborne pathogens have been implemented, including the use of antibiotics.

However, there is great concern about the widespread use of antibiotics in animal production leading to the emergence of antimicrobial resistance, and it also poses a potential risk to public health.

As a result, an increase in the rate and severity of In recent years, substantial scientific evidence has shown that the use of certain antibiotics increases enteric colonization of antibiotic-

these infections in food-producing animals as well as in humans has been reported in many countries around the world.

resistant strains of enteric pathogens in domestic

Antibiotics are ineffective in the treatment of multi

animals.

drug resistant bacteria.

45 aviNews International May 2020 | Alternatives to Antimicrobial Growth Promoters in Poultry

nutrition

fatalities each year.

Equally frightening, is the fact that indiscriminate use of antibiotics can actually induce disruption of the intestinal microbiome, reducing the production of short chain fatty acids and increasing luminal pH in the distal gastrointestinal tract (dysbacteriosis).

The results of this study, together with those obtained in previous studies focusing on other antibiotics and enteric pathogens, suggest that the prophylactic use of some antibiotics in poultry increases the susceptibility to salmonella colonization and organ invasion.

nutrition

Resultados

In a recent study published in Frontiers in Veterinary Science -2016-, we evaluate the risk of infection with Salmonella Enteritidis -SE- or Salmonella Heidelberg -SH- associated with the use of Enrofloxacin in commercial birds, and we checked the effects of a probiotic as an alternative to antibiotics..

The use of antibiotics should be limited to the treatment of infections caused by a specific bacterium and with the antibiotic to which it is known to be sensitive.

Our findings also confirm the results of numerous studies, which suggest that the use of alternatives such as probiotics can be an effective tool for the control of salmonellosis.

Gut microbiota & antibiotic limitations The microbiome plays a vital role in various

Microbiome and its host, are working as one

physiological, immunological and metabolic

single organism. One of the fascinating aspects

activities of hosts. However, very little is known

of this mutualism is the impact in the regulation

about possible mechanisms involved between

of inflammatory responses.

bacteria and hosts in order to maintain their homeostasis in the gut.

Enterocytes, not only participate in digestion and absorption of nutrients, but they also participate

Many factors including nutrient composition,

as antigen presenting cells and regulates gut

stress and antibiotics can alter the

permeability.

microbiome.

The hostâ&#x20AC;&#x2122;s intestinal epithelial cells provide

Production of IgA by

both physical and chemical barriers to

plasma cells, forming

pathogenic bacteria through:

tight intercellular junction

Production of mucus from goblet cells Secretion of antimicrobial peptides from Paneth cells

complexes Recognition of microbeassociated molecular pattern

46 aviNews International May 2020 | Alternatives to Antimicrobial Growth Promoters in Poultry

Microbiota

Loss of effectiveness of antibiotics The loss of effectiveness of antibiotics - the miracle drugs of the 20th century - has become an imminent danger to public health.

Consequently, in 1997 the World Health Organization - WHO - published a list of antibiotics that should be reserved only for human use.

Consequently, the World Health Organization (WHO) published a list of antibiotics that should

Host

be reserved for human use only. Interestingly, soon after the publication of the WHO report, and with growing consumer and scientific pressures, the European Union went one step further, creating new legislations banning the use of all antibiotics as growth promoters as of January 2006.

Eleven years later, focusing on the concept of “One Health” as a way to combat antimicrobial

nutrition

Our understanding of several possible mechanisms involved in gut bacterial homeostasis should be widened in order to modulate their composition or treat diseases.

resistance and to preserve antibiotics important to human medicine, the US Food and Drug Administration. USA –FDA– banned the use of

Microbiota balance The fragile balance of the microbiota is

antibiotics critical to human medicine as growth promoters and expanded the list of antibiotics for foods classified as veterinary drugs.

influenced by many factors such as: Delivery method Age Dietary nutrient composition Infections Inflammation Stress Medication

It is therefore, not surprising to see that as a result of the indiscriminate use and abuse of antibiotics, the incidence of some food-borne pathogens such Salmonella and Campylobacter are increasing worldwide, with reports of antibiotic resistance in clinical isolates of these and other enteric pathogens.

47 aviNews International May 2020 | Alternatives to Antimicrobial Growth Promoters in Poultry

Currently, it is estimated that almost 50% of US poultry companies have eliminated the use of antibiotics - both growth promoters and preventively - in their production programs.

50

% poultry companies in the USA have eliminated the use of antibiotics

However, in some countries, the indiscriminate use and misuse of antibiotics are still a sad reality, particularly where there is no legislation regulating the use of

nutrition

antibiotic in animal agriculture.

Alternatives to antibiotics & field experiences

Probiotics Prebiotics are non-digestible food ingredients (readily fermentable sugars), that beneficially affect the host by selectively stimulating the

Over a century ago Eli Metchnikoff (1907) proposed

growth and/or activity of one or a limited

the revolutionary idea to consume viable bacteria

number of bacteria in the colon, and thus

to promote health by modulating the intestinal

improve host health.

microflora. The idea is more applicable now than ever since bacterial antimicrobial resistance has become a serious worldwide problem both in medical and agricultural fields..

Most potential prebiotics are carbohydrates such as: Oligosaccharides Fructo-oligo-saccharides (FOS)

Hence, the poultry industry has been evaluating the use of antibiotic alternatives.

Xylo-oligo-saccharides (XOS)

The most studied are: Probiotics (water

Mannan-oligo-saccharides (MOS)

application mainly lactic acid bacteria) or

Galacto-oligo- saccharides

Direct-fed microbials, Bacillus spore based balance gut microflora.

Synbiotics refers to the appropriate combinations of pre- and probiotics.

48 aviNews International May 2020 | Alternatives to Antimicrobial Growth Promoters in Poultry

nutrition

Acidifiers / organic acids Acidifiers/Organic acids include short chain fatty acids, volatile fatty acids and weak carboxylic acids that are only partly disassociated. They may play a role in maintaining gut integrity:

Reducing the colonization of pathogens promoting the normal microbiome growth

Daily application of short chain fatty acids such as Butyric acids increases epithelial cell proliferation, quick repairing of the intestine, increased villous height and in turn increased absorptive capacity

Enzymes

Increasing the efficiency of all

Enzymes can improve digestibility, particularly

digestive enzymes

of grains containing high levels of non-starch polysaccharides: Increase intestinal viscosity Favoring dysbiosis Reducing the absorption of nutrients Producing sticky feces and dirty eggs

49 aviNews International May 2020 | Alternatives to Antimicrobial Growth Promoters in Poultry

Toxin binders Toxin binders are used through feed to bind or adsorb deleterious substances such as mold and fungi-borne mycotoxins that have negative impact in the health of the host and the microbiome.

In recent years, live and inactivated vaccines have been used against Salmonella spp. in breeders to reduce the prevalence of infection and the risk of transmission.

Numerous studies and field experiences have shown that broilers from breeders vaccinated against Salmonella have a lower prevalence of salmonellosis at birth, during the growth phase and before processing.

nutrition

Evidently, there is no such thing as a silver bullet. Rather, the combination of several of these nutraceuticals, accompanied with good husbandry and management practices oriented to improve biosecurity programs are becoming the new strategies incorporated in many companies.

Table 1. Alternatives to growth-promoting antibiotics in birds.

Product

Administration route

Probiotics

Water

Prebiotics

Food

Sybiotics

Water and / or Food

Acidifiers / Organic Acids

Water and / or Food

Enzymes

Food

Mycotoxins

Food

Live and inactivated vaccines

Water, nebulization, subcutaneous injection

Essential oils

Water and / or Food

Aromatic plants

Water and / or Food

In addition to improving the balance of the intestinal microbiota, the metabolism and the integrity of the intestinal wall, several studies have also revealed that some products used as alternatives to growthpromoting antibiotics â&#x20AC;&#x201C;See Table 1â&#x20AC;&#x201C; have anti-inflammatory and antioxidant properties, and improve the integrity of the intestinal barrier.

50 aviNews International May 2020 | Alternatives to Antimicrobial Growth Promoters in Poultry

The field experiences presented at a recent sectoral meeting Sustainable Poultry Production, Production, Nutrition and Pharmacology Workshop 2017, Queretaro, Mexico - showed that broilers raised with an antibiotic-free program in Mexico had better performance, lower mortality and better relationship. costbenefits compared to conventional programs.

These broiler farms used live vaccines against coccidiosis, prebiotics, probiotics, organic acids, and essential oils. It also included a strict biosecurity program and free breeding stock of Mycoplasma spp. and Salmonella spp., and with strong maternal immunity against various diseases.

nutrition

The experience of a Colombian company, comparing the costs of cage production versus cage-free farms, revealed that cage-free hens were healthier, produced more eggs / hen, and consumed less feed thanks to following a strict combined biosecurity program. with the use of probiotics, prebiotics, organic acids, essential oils, and vaccines against coccidiosis and Salmonella spp.

Under commercial conditions, chickens and turkeys are often born in challenging environments and where they are exposed to heat stress and potential pathogens in hatcheries. Stress, together with the abundance of pathogens in the incubator, provides the ideal conditions for colonization of the birdsâ&#x20AC;&#x2122; intestine with these microorganisms. To minimize this situation, several researchers have shown that in ovo administration of probiotics, prebiotics or synobiotics can have a significant impact on the development of a normal intestinal microbiota in birds.

Also, some researchers have confirmed the benefits of probiotics on innate and humoral immunity. In summary, the growing scientific knowledge and experiences in commercial production demonstrate that there are new viable and alternative methods for the production of healthy, antibiotic-free, safe and affordable poultry products.

Alternatives to Antimicrobial Growth Promoters in Poultry DESCĂ RGALO EN PDF

51 aviNews International May 2020 | Alternatives to Antimicrobial Growth Promoters in Poultry

FREQUENTLY ASKED QUESTIONS ABOUT THE CORONAVIRUS BASED OF WHAT WE

KNOW ABOUT THE AVIAN CORONAVIRUS INFECTIOUS BRONCHITIS VIRUS (IBV) animal health

Mark W. Jackwood, MS, Ph.D. Department of Population Health, Poultry Diagnostic and Research Center, College of Veterinary Medicine, 953 College Station Road, University of Georgia, Athens, GA 30602, USA

What we know about avian coronavirus infectious bronchitis virus (IBV) in poultry â&#x20AC;&#x201D; and how that knowledge relates to the virus causing COVID-19 in humans

52 aviNews International May 2020 | Frequently asked questions about the coronavirus based on what we know about the avian infectious bronchitis virus (IBV)

To better understand the challenges associated with the COVID-19 disease in humans, poultry health professionals can draw on their many years of experience attempting to control avian coronavirus infectious bronchitis (IBV) in poultry.

Coronaviruses are divided into Alpha-, Beta-, Gamma- and Delta- coronavirus groups. Coronaviruses are responsible for a wide variety of existing and emerging diseases in humans and other mammals (including food animals) as well as in birds (including poultry).

Diseases associated with coronavirus infections cover a wide range including respiratory, enteric, neurological, renal and hepatic.

The coronavirus that affects poultry (IBV) and causes respiratory disease in chickens is in the avian Gammacoronavirus group. Avian viruses in the Gammacoronavirus group do not infect or cause disease in humans. The COVID-19 virus is in the Betacoronavirus group along with SARS-CoV and MERS-CoV.

It was previously shown that SARSCoV does not infect or cause disease in poultry (Swayne et al. Emerging Infectious Diseases Vol. 10, No 5, May 2004) Because the COVID-19 virus belongs to the same group as SARS-CoV and uses the same ACE-2 host cell receptor, it is highly unlikely that the COVID-19 virus will infect or cause disease in poultry, but it remains to be scientifically proven.

53 aviNews International May 2020 | Frequently asked questions about the coronavirus based on what we know about the avian infectious bronchitis virus (IBV)

animal health

Itâ&#x20AC;&#x2122;s important to emphasize that the COVID-19 virus (SARS-CoV-2) is not associated with poultry or poultry products.

Based on the knowledge at hand, and the current lack of any evidence of bird infections with the COVID- 19 virus, poultry and poultry products are not considered to be a source of COVID-19 infection for humans.

The COVID-19 virus is primarily spread among people via respiratory droplets that contain the virus, with infections occurring via the nose, eyes and mouth.

Although highly infectious, it is an enveloped virus â&#x20AC;&#x201D; one that is easily killed by soap and common disinfectants. Below are some frequently asked questions regarding

animal health

coronaviruses.

Where do coronaviruses come from?

Bats are widely accepted as the reservoir for mammalian (Alpha- and Beta-) coronaviruses. There are about 1,240 different bat species harboring as many or more different coronavirus types. SARSCoV and MERS-CoV came from a bat reservoir, infected an intermediate host then jumped to humans.

It is likely that the COVID-19 virus

The reservoir for avian coronaviruses,

originated from bats, furthermore,

including IBV, is not clear. There are

preliminary data show some viruses

some closely related viruses in wild and

isolated from bats to be close relatives.

domestic birds â&#x20AC;&#x201D; pheasants, ducks,

An intermediate host for the COVID-19 virus has not been identified yet.

geese and pigeons, to name a few â&#x20AC;&#x201D; but unequivocal evidence of a true reservoir is lacking

54 aviNews International May 2020 | Frequently asked questions about the coronavirus based on what we know about the avian infectious bronchitis virus (IBV)

Why is it difficult to produce a vaccine against coronaviruses?

Protective immunity against a respiratory disease like infectious bronchitis (IB) in poultry or COVID-19 in humans requires a strong local immune response.

In poultry, we achieve this by using live attenuated vaccines, but live produce because attenuation often renders them unable to produce a strong local immune response.

What about using killed vaccines against coronaviruses?

There are killed (inactivated) vaccines against

Attenuation is accomplished by passage

IBV for poultry, however they are also difficult

of the virus in a laboratory host system

to develop.

(embryonating chicken eggs or cell culture), but there is a fine line between attenuation and maintaining the viruses ability to infect and induce an immune response.

Chemicals such as formalin or betaPropiolactone used to kill the virus also can destroy the integrity of the spikes, thus yielding a vaccine that does not induce a protective immune response.

In addition, for killed vaccines to be effective,

Excessive attenuation It makes the vaccine safe but not

they must be given after a live attenuated â&#x20AC;&#x153;primingâ&#x20AC;? vaccine, which, as discussed above, has significant safety issues.

immunogenic..

In humans, killed vaccines against Lack of attenuation

respiratory viruses are used, for example against influenza virus, but this

Will create a vaccine capable of

requires growing the virus to high titers,

inducing a strong immune response

inactivating it and using safe adjuvants.

but may cause a severe vaccine

This has proved difficult to achieve for

reaction.

human coronaviruses.

Then there is the problem of back passage of the vaccine in the host leading to a pathogenic virus.

Based on our knowledge of producing vaccines against IBV, production of a live attenuated vaccine against COVID-19 with acceptable safety and efficacy may prove to be very difficult.

55 aviNews International May 2020 | Frequently asked questions about the coronavirus based on what we know about the avian infectious bronchitis virus (IBV)

animal health

coronavirus vaccines are difficult to

Why donâ&#x20AC;&#x2122;t we have recombinant vaccines against IBV in poultry?

And could a recombinant vaccine be developed for the COVID-19 virus?

The coronavirus surface-spike glycoproteins are embedded in a lipid envelope and have conformationally dependent epitopes that induce neutralizing antibodies in the host.

When the spike protein is removed from the virus envelope or when it is expressed in a laboratory system, those conformationally dependent epitopes are not faithfully reproduced.

Thus, vectors such as fowl pox and herpesvirus of turkeys have not been

animal health

suitable vaccine platforms for expressing coronavirus spikes.

Spike protein production by the virus in a natural infection is very specific and difficult to mimic, thus other recombinant vaccines, such as DNA vaccines, RNA vaccines and

Then there are genetically altered coronavirus vaccines derived from infectious clones.

Making changes to the genome of the pathogenic virus to create a safe, attenuated live coronavirus vaccine that is still capable of inducing an effective immune response is complex and often results in non-viable viruses or insufficient protection. It can be a fast track to finding a vaccine candidate, but the safety of these live vaccines must be rigorously tested.

Fortunately, it is not all bad news. The immune system of a bird is very different from that of a human. What doesnâ&#x20AC;&#x2122;t work in poultry may actually work well in humans.

In addition, financially we can do a lot more in development and delivery of vaccines in humans than in poultry, where tight margins make it necessary for vaccines to improve the welfare of the flock while still yielding a satisfactory return on investment.

subunit vaccines, do not accurately reproduce spike.

Additionally, these vaccines usually do not stimulate adequate local immunity and have to be given many times to provide any protection.

The goals and performance parameters for human vaccines are obviously much different than production agriculture.

Currently, there are many different coronavirus vaccines and platforms being developed or optimized for human use.

56 aviNews International May 2020 | Frequently asked questions about the coronavirus based on what we know about the avian infectious bronchitis virus (IBV)

How do different serotypes/genetic types of coronavirus complicate vaccine development?

In poultry, there are many types (serotypes/ genetic types) of IBV that do not cross protect.

Consequently, recovery from one type does not immunize the bird against another type.

Are there treatments for coronaviruses?

For humans, we have antiviral drugs like oseltamivir (Tamiflu) for Influenza, but there have not been any successful drugs developed specifically for coronaviruses. Drugs against the viral-encoded proteases have been tried, as well as drugs that interfere with entry and

For this reason, we have had to develop

egress of the virus from the host cell. These and

a number of different IBV vaccines (Ark,

many other potential antivirals are presently

Mass, Conn, DE, etc.) to control the disease.

being tested by several companies.

one type of COVID-19 virus circulating in humans.

However, full genome sequencing has shown that the virus is changing. A number of mutations have been observed, but none appear to be maintained at this time, which suggests they are not important for transmission or virulence. From a vaccine standpoint, only one type of COVID-19 virus circulating in humans means that only one vaccine type should be needed to protect against this disease

Two drugs currently in the news, chloroquine and hydroxychloroquine are being examined for their ability to ameliorate COVID-19 infections.

animal health

Fortunately, there appears to be only

These drugs have been used against malaria, lupus and rheumatoid arthritis for many years. Preliminary data out of China indicate that the drugs stop the spread of the COVID-19 virus in cell culture and are somewhat effective in treating humans.

But, until controlled clinical trials are conducted, their effectiveness against COVID-19 remains a question.

57 aviNews International May 2020 | Frequently asked questions about the coronavirus based on what we know about the avian infectious bronchitis virus (IBV)

animal health

+

It is likely that this pandemic will not be over anytime soon. In the meantime, follow the Centers for Disease Control and World Health Organization recommendations to protect yourself and your family. Poultry flocks do not appear to be at risk.

his statement was developed on behalf of the American Association of Avian Pathologists, an international association whose mission is to promote scientific knowledge to enhance the health, well-being, and productivity of poultry to provide safe and abundant food for the world.

For more information, visit aaap.info.

Frequently asked questions about the coronavirus based on what we know about the avian coronavirus infectious bronchitis virus (IBV)

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58 aviNews International May 2020 | Frequently asked questions about the coronavirus based on what we know about the avian infectious bronchitis virus (IBV)

GALLIBACTERIUM ANATIS AN EMERGING PATHOGEN

OF

POULTRY?

Natalie K. Armour & Martha Pulido-LandĂ­nez Poultry Research and Diagnostic Laboratory, Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University

pathology

G

allibacterium anatis bv, haemolytica (formerly Pasteurella haemolytica) occurs as a commensal of the upper respiratory tract and lower reproductive tract of healthy chickens, but has also been implicated as a cause of salpingitis and peritonitis in breeders and commercial table egg layers in multiple countries, resulting in decreased egg production and increased mortality.

Recent increases in isolation and reports of significant disease, mortality and economic loss associated with G. anatis infection suggest that this bacterium may be an emerging pathogen of poultry.

59 aviNews International May 2020 | Gallibacterium anatis â&#x20AC;&#x201C; An Emerging Pathogen of Poultry?

Biovars of G. anatis Gallibacterium anatis, a member of the family Pasteurellaceae, has two distinct biovars; G. anatis bv. haemolytica y G. anatis bv. anatis.

The pathologically significant G. anatis bv. haemolytica, named for its ability to hemolyze red blood cells, was previously designated Pasteurella haemolytica.

G. anatis is a cause of salpingitis and peritonitis in laying chickens, and has also been isolated as a cause of disease in ducks, geese and ostriches.

The Commensal to Pathogen Switch pathology

Although increasingly identified as a cause of disease in chickens, particularly in laying hens –Graph 1–, the pathogenic potential of G. anatis remains controversial.

On the one hand, G. anatis may occur as a normal part of the microbiota of the upper respiratory tract and lower reproductive tract of chickens, without any adverse effects on health or productivity.

G. anatis has, however, been identified as a cause of septicemia, pericarditis, hepatitis, oophoritis, salpingitis, peritonitis and follicle degeneration, with subsequent significant negative effects on flock livability and productivity

40 35 30 Nº of isolations

Graph 1. Isolation of Gallibacterium anatis at the PRDL (Poultry Research and Diagnostic Laboratory, Mississippi State University)

25 20 15 10 5 0 Jul-Dec 2015

Jan-Jun 2016 Jul-Dec 2016 Time period

60 aviNews International May 2020 | Gallibacterium anatis – An Emerging Pathogen of Poultry?

Jan-Jun 2017

Factors contributing to the potential pathogenic action of G. anatis While the switch from commensal to pathogen is not fully understood, several host- specific factors may contribute to the manifestation of G. anatis as an opportunistic pathogen including: Age Hormonal influences Stress Seasonal changes

Strain Diversity In addition to these extrinsic factors, intrinsic, strain-specific characteristics of the bacterium appear to be of great importance in determining the presentation and significance of G. anatis infection.

Immune suppression

We most commonly isolate G. anatis from breeders and layers around peak egg production, although isolations have been made during all stages of production G. anatis is frequently isolated with E. coli, and it is plausible that coinfection with E. coli or other microorganisms may enhance the pathogenic effects of G. anatis. G. anatis may, however, they can also be isolated from lesions in pure culture.

Studies using molecular strain differentiation techniques have identified multiple strains of G. anatis, with apparent wide variations in strain virulence

pathology

Genetic predisposition (possibly)

G. anatis strain differentiation is an important tool to facilitate outbreak investigations, epidemiologic studies and targeted vaccine development.

Of the broiler breeder necropsy cases from which G. anatis was isolated during the past 2 years at the PRDL (Poultry Research and Diagnostic Laboratory, Mississippi State University), 50% involved G. anatis only; while G. anatis was isolated together with E. coli from the remaining 50% of cases.

61 aviNews International May 2020 | Gallibacterium anatis â&#x20AC;&#x201C; An Emerging Pathogen of Poultry?

Horizontal vs. vertical transmission

Epizootiology While horizontal transmission is accepted as the primary mode of transmission between flocks, there is some evidence to support the possibility of vertical (trans- ovarian) transmission of G. anatis.

At the PRDL, G. anatis has been isolated with E. coli from the brains of 4-day-old broiler chicks with encephalitis. This may be the youngest reported isolation of G. anatis, and raises the question of whether trans- ovarian transmission occurred in this case.

Virulence Factors Strain differences in the expression of virulence factors may explain the diverse presentation of G. anatis infection. Research is ongoing to identify virulence factors of G. anatis, which will elucidate the pathogenesis of this organism, and may prove useful for vaccine development: The secreted toxin GtxA (Gallibacterium toxin A), the most well characterized virulence factor of G. anatis, has hemolytic and leukotoxic activity.

FlfA fimbriae of the F17-like family have also been shown to be important for G. anatis virulence.

pathology

Ascending infections from the cloaca are considered the most likely route of infection of the reproductive tracts of laying hens, but frequent isolation of G. anatis from the respiratory tract, and the ability to reproduce lesions in the reproductive tract by intranasal challenge with G. anatis suggest that infection via the respiratory route may occur under some circumstances.

Other potential virulence factors include the ability of G. anatis to produce capsular material, secrete metalloproteases capable of degrading chicken IgG, produce biofilms and hemagglutinate erythrocytes.

Interestingly, G. anatis has been isolated from the testes and semen of intranasally infected cockerels, suggesting a possible role of cockerels in G. anatis transmission

62 aviNews International May 2020 | Gallibacterium anatis â&#x20AC;&#x201C; An Emerging Pathogen of Poultry?

Clinical Signs and Pathology

Figure 1. Gallibacterium anatis Perihepatitis

G. anatis is increasingly recognized as an important cause of salpingitis and peritonitis in laying hens, resulting in mortality and decreased egg production.

After the natural and experimental infection of breeding and laying hens, the following has been observed: Hepatitis –Figure 1–.

Figure 2. Foliculitis, with yolk in the coelomic cavity associated with G. anatis infection

Upper respiratory tract lesions.

Folliculitis with ovarian follicle hemorrhage, rupture, and regression, yolk in the coelomic cavity –Figure 2–.

Peritonitis and salpingitis –Figure 3–.

Oviduct hemorrhages and drops in egg production pathology

Figure 3.

Gallibacterium anatis peritonitis and salpingitis

The lesions associated with G. anatis infection are not pathognomonic, and may be indistinguishable from those caused by E. coli.

This has been demonstrated for Infectious Coryza, with exacerbated disease and mortality produced by coinfection with Avibacterium paragallinarum and G. anatis

Coinfection with G. anatis and other poultry pathogens

Can increase disease severity

In commercial brown layers in Latin America diagnosed with fowl typhoid (caused by Salmonella Gallinarum), G. anatis was isolated from the tracheas, lungs, ovarian follicles and oviducts. Mortality and egg production drops were higher in houses infected with both Salmonella Gallinarum and G. anatis than in those infected with Salmonella Gallinarum alone. In addition to clinical signs associated with fowl typhoid, birds infected with both Salmonella Gallinarum and G. anatis had more evidence of respiratory disease.

63 aviNews International May 2020 | Gallibacterium anatis – An Emerging Pathogen of Poultry?

Figure 4a. G. anatis and E. coli septicemia: Hemorrhage of the epicardium, myocardium and coronary fat At the PRDL, we recently determined the cause of high mortality in a flock of 42-week- old broiler breeder chickens to be a dual infection with G. anatis and E. coli O128:H14.

Daily mortality in the worst affected house peaked at 2.36% (231 birds), and was preceeded by a 16% drop in hen-day egg production over a period of 10 days.

pathology

Hemorrhagic lesions were observed in multiple internal organs, including ovarian follicles and viscera –Figures 4a-d–, as a result of severe multiorgan bacteremia with vasculitis, which was confirmed histologically –Figure 4e–.

Figure 4b. G. anatis and E. coli septicemia: Proventricular hemorrhage

Figure 4c. G. anatis and E. coli septicemia: Intestinal hemorrhage

G. anatis and E. coli were isolated from the spleen and bone marrow samples; no other pathogens were detected following bacterial culture, virus isolation and PCR.

Figure 4d.G. anatis and E. coli septicemia: Folliculitis and ovarian follicle hemorrhage

Figure 4e.G. anatis and E. coli septicemia: Lung – Intravascular bacterial embolus (200x; H&E stain) (Image: Dr. B. Baughman)

64 aviNews International May 2020 | Gallibacterium anatis – An Emerging Pathogen of Poultry?

Antimicrobial Treatment and Resistance G. anatis is notorious for its widespread antimicrobial resistance, presenting a challenge to treatment. This underscores the importance of performing bacterial culture and identification, with antimicrobial sensitivity (antibiogram) testing to facilitate targeted flock treatment.

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

Resistant Intermediate

Am

ox Ce icillin Cli ftio n En dam fur r Ery ofloxycin thr aci o n Flo myci r Ge fen n nta ico Ne mici l om n Ox Nov ycin yte obi tra oci cy n Sp Pen cline ect ic i il Su Stre nom lin lfa pt yci dim om n Su etho ycin lfa xi Tet thiaz ne rac ole y Su cline lfa tr Tyl im osi n

pathology

Sensitive

Graph 2. Antimicrobial sensitivity of 49 recent G. anatis isolates evaluated at PRDL

46 of 49 (94%) G. anatis isolates evaluated recently at PRDL were determined to be multi-drug resistant (resistant to 3 or more antimicrobials) –Gráfica 2–: General resistance to clindamycin, novobiocin, tetracyclines, and tylosin.

General sensitivity to aminoglycosides, ceftiofur, enrofloxacin, florfenicol, and sulfatrimethoprim.

Intermediate sensitivity to erythromycin, spectinomycin, and sulfathiazole.

Variable resistance to β-lactams and sulfadimethoxine.

Similar findings have been reported by others.

65 aviNews International May 2020 | Gallibacterium anatis – An Emerging Pathogen of Poultry?

pathology

Prevention and Control As with other poultry diseases, excellent biosecurity, high standards of flock management, the provision of a suitable environment, and attention to bird welfare are important tools for the prevention and control of G. anatis infections.

Since G. anatis frequently manifests as an opportunistic pathogen, prevention and control of immunosuppression and other diseases is important.

The development of successful G. anatis vaccines is challenging because of the high antigenic diversity of this bacterium, and there have been some concerns about the performance of these vaccines under field conditions.

G. anatis bacterin vaccines (usually containing the most prevalent strains in a particular region or country) are currently in use in some countries.

Considering the demonstrated ability of G. anatis to form biofilms, special measures to prevent biofilm formation must be implemented, including excellent water quality and regular water line cleaning and disinfection.

66 aviNews International May 2020 | Gallibacterium anatis â&#x20AC;&#x201C; An Emerging Pathogen of Poultry?

Subunit and outer membrane vesicle vaccines have been developed and used experimentally

The emergence in recent years of G. anatis as a pathogen of significance to poultry production has been driven by increased G. anatis isolations and more frequent reports of severe disease, mortality and egg production losses

pathology

Recent research has increased our understanding of G. anatis strain diversity and virulence factors, but much remains to be learnt about the epizootiology and pathogenesis of this organism

Widespread resistance of G. anatis isolates to antimicrobial drugs highlights the need for alternative control strategies, including the continued development and application of safe and efficacious vaccines

Gallibacterium anatis â&#x20AC;&#x201C; An Emerging Pathogen of Poultry?

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References in this article are available upon request

67 aviNews International May 2020 | Gallibacterium anatis â&#x20AC;&#x201C; An Emerging Pathogen of Poultry?

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