NUTRITION diet resulted in comparable final body weight, SGR and weight gain with control diet. The positive attributes of poultry hydrolyzed protein meal are that it promotes better feed utilization and nutrient absorption in carnivorous species like the hybrid grouper to improve nutrient uptake. Several studies have shown that protein hydrolysates enhance nonspecific immunity in fish and are an interesting alternative to antibiotics for controlling the propagation of infectious diseases. The in vitro stimulatory effect of some protein hydrolysates on fish leucocytes suggests that the inclusion could be effective in reducing disease-related losses among farmed fish (Martínez-Alvarez et al., 2012). Generally, aquafeed formulation with krill meal can enhance feeding and fish growth performance. Dietary incorporation of krill meal increased the stimulation and showed higher feed consumption than the control diet. Krill meal is rich in chitin from the exoskeleton and soluble compounds like trimethylamine oxide (TMAO), free amino acids and nucleotides that may all act as feeding stimulants. The presence of the natural astaxanthin in krill meal act as an antioxidant to offer health benefits and disease resistance, especially under intense condition (Nunes et al., 2020). Polychaete meal are considered to have a wellbalanced nutritional profile. The nutritional value of polychaete meal has been specifically attributed to the high content of protein and n-3 polyunsaturated fatty acids (ARA, EPA and DHA), which have been proven to be an important vector to transfer essential fatty acids to marine fish particularly hybrid grouper in current test diet. The bromophenols appeared to be essential ingredients in marine fish aquafeed due to their function on satisfactory feed intake that is similar to natural ‘ocean flavor’ (Cameron, 2014). The fermented soybean meal improves intestinal health, promotes immunity and enhances disease resistance without negative effects on carnivorous fish growth including other grouper species (Einstein-Curtis, 2019). It promoted better intestinal absorption for nutrient uptake due to its key mechanism of the digestive enzyme to help digest cellulose when fish were fed high plant-based diets. Furthermore, the proper inclusion of fermented soybean meal improved the resistance to bacterial infection (Yang et al., 2022). In hybrid grouper trial 3, the same blended ingredients in trial 1 were used, however, there were some
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limitations observed in the total fish performances. The nutrient limitation in the test diet and fish size difference might affect the digestibility tolerance of hybrid grouper when challenged under the intensification system. Current trials on red tilapia and hybrid grouper feed use a combination of highly digestible protein sources, high-quality ingredients and feed additives to produce high-quality feed has resulted in relatively better fish performances compared to the control feed in some trials. These results proved that the formulation and chemical composition of tested diets were promising and effective to improve the fish’s growth performances.
Conclusion The ingredients used to formulate this “novel” fish feed for super-intensive systems have shown a significant and relatively better improvement in fish growth performances. The combination of different protein sources can reduce the overreliance on fisheries-based protein, produce cost-effective formulated feed and stimulate selected growth promoters to fulfill the nutrient requirement to achieve maximum production efficiency in an intensive system. This novel feed can optimize production efficiency, mitigate the environmental impact and improve fish resilience and welfare. Blue Aqua International has developed BlueFeed for Marine Fish to cater to the nutritional gap in highperformance culture methods. These trials will drive the industry to produce more super high-quality feed to support the aquaculture industry. References available on request.
More information: Dr. Farshad Shishehchian CEO & Co-Founder Blue Aqua International E: info@blueaquaint.com
Hatchery Feed & Management Vol 11 Issue 1 2023