Quantitative dietary requirements of postlarval tiger shrimp, Penaeus monodon, for histidine, isoleucine, leucine, phenylalanine and tryptophan

The quantitative requirements of postlarvae Penaeus monodon for essential a mino acids were determined through a series of feeding experiments. Test di ets contained casein-gelatin as natural proteins supplemented with crystall ine L-amino acids (CAAs) at levels based upon the tissue amino acid profile of postlarvae tiger shrimp. Each set of experimental diets contained grade d levels of the test amino acid in a range below and above those found in s hrimp muscle protein. The dietary CAA mixture was pre-coated with carboxyme thylcellulose (CMC), and the diets were additionally bound with CMC, corn s tarch, and K-carrageenan to prevent leaching of amino acids and other nutri ents. P. monodon postlarvae, PL20, mean body weight of 20 mg, were randomly distributed to 30-1 fiberglass tanks at a density of 10/tank and each grou p was fed a particular diet for 56 days. A one-way analysis of variance was used to determine if there were any significant differences in weight gain , survival, and feed conversion among the dietary treatments for each exper iments. Regression analysis of the weight gain responses against dietary am ino acid levels was used to estimate the amino acid requirements. The optim um dietary requirements for essential amino acids, in percent of the diet, were: 0.8% histidine, 1.01% isoleucine, 1.7% leucine, 1.4% phenylalanine, a nd 0.2% tryptophan. Expressed as percent of the dietary protein, the requir ement values were: 2.2% histidine, 2.7% isoleucine, 4.3% leucine, 3.7% phen ylalanine, and 0.5% tryptophan. This information is crucial in optimizing g rowth and feed efficiency and in developing cost-effective diets for P. mon odon. (C) 1999 Elsevier Science B.V. All rights reserved.