Sequence in Which the Amino Acids of Fish Meal Protein Become Limiting for the Growing Chicken, as Determined by “The Complete Protein Evaluation Method”

Abstract

The complete protein evaluation method (CPE) of Schelling (1975) was modified and tested on chicks with two capelin fish meals, A and B, which were produced from the same catch. However, the raw materials were preserved in different manners (fish meal A with a formaldehyde/sodium nitrite solution for 6 days and fish meal B on ice for 4 days, respectively). In a single experiment for each fish meal, the modified method indicated the complete sequence in which the amino acids became limiting for the growing chicken. The CPE results were verified by additional supplementation experiments. The results indicated the two following sequences for the amino acid limitation: Fish meal A: methionine = histidine > phenylalanine = arginine > isoleucine = tryptophan > threonine > leucine = valine = lysine > glycine. Fish meal B: phenylalanine = arginine = methionine > histidine > tryptophan = isoleucine > valine > leucine = threonine > lysine = glycine. The results also indicated that the quality of fish meal A was poorer than that in fish meal B. In conclusion, it was found that the modified CPE method possesses a potential for detecting the sequence of limiting amino acids in fish meal protein.