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A sustainable mix of free amino acids improves shrimp feeding behavior Pierrick Kersanté, Joël Duperray, BCF Life Sciences, Guillaume Le Reste, Halieutica
Apart from being an essential nutrient for protein synthesis, amino acids are among the few molecules known for their ability to attract aquatic animals. This functionality is of particular importance for shrimp as they exhibit a relatively slow feeding behavior. This habit can be reinforced by the current trend of marine raw material substitution given that vegetable-sourced ingredients are generally less attractant and palatable. Anyone who has already thrown a shrimp feed pellet into water has observed that some components leak out of the pellet quite rapidly and start to dye water. This phenomenon, called lixiviation, is a major source of loss for the farmer and a source of pollution for pond water. Feed formulators and technologists have worked together to improve pellet water stability but lixiviation remains unavoidable as some water-soluble essential nutrients must be added to the feed (some vitamins, minerals, amino acids, etc). Therefore, increasing feed palatability constitutes one of the most efficient ways to sustain feed efficiency.
Mix of free amino acids and shrimp feeding behavior Poultry keratin is a major industrial co-product. The extensive hydrolysis of this sustainable but hardly digestible protein results in an interesting mix of free
Table 1. Amino acids contained in the MFAA with the proportion of each AA under a free form.
Total amino acids Free AA/total Aspartic acid 3.67 100% Threonine 2.48 98% Serine 6.60 100% Glutamic acid 5.43 97% Glycine 4.48 96% Alanine 2.53 98% Valine 4.07 71% Cystine 1.04 60% Methionine 0.30 86% Isoleucine 2.44 76% Leucine 3.96 94% Tyrosine 0.41 86% Phenylalanine 2.49 97% Lysine 0.97 94% Histidine 0.32 100% Arginine 3.40 95% Proline 5.84 100% amino acids (MFAA). Thanks to its richness in free amino acids, the MFAA Kera-Stim®50 (Table 1) can be considered as a possible palatability enhancer in shrimp. Such a product has already been tested in
Table 2. Experimental plan.
Fishmeal content Control diets Kera-Stim®50 Coated Mixed
FM15% FM7.5% FM0% F15-Ctrl F7.5-Ctrl F0-Ctrl F15-AA-Ctd F7.5-AA-Ctd F0-AA-Ctd F15-AA-Mix F7.5-AA-Mix F0-AA-Mix
Aquafeed: Advances in Processing & Formulation Vol 12 Issue 4 2020
