|Craig, S - VIRGINIA TECH UNIVERSITY|
|Mclean, E - VIRGINIA TECH UNIVERSITY|
Submitted to: Fish Nutrition and Feeding Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2006
Publication Date: May 28, 2006
Repository URL: http://riley.nal.usda.gov/nal_web/digi/submission.html
Citation: Craig, S.R., Gaylord, T.G., Mclean, E. 2006. Aquacat: a taurine requirement for cobia.. Fish Nutrition and Feeding Symposium Proceedings XII International Symposium On Fish Nutrition and Feeding. Biarritz, France, 28 May - 1 June 2006 Technical Abstract: In most animals, taurine is synthesized from methionine and cysteine. However, due to inadequacy of enzymatic machinery involved in taurine synthesis, it is considered an essential amino acid (EAA) for cats. Cobia (Rachycentron canadum) are marine carnivorous fishes with global distribution. In fish meal replacement studies utilizing a yeast-based protein source, juvenile cobia were fed diets containing incrementally higher levels of the alternate protein source (25, 50, 75, and 100% replacement of fish meal). At levels of 50% inclusion or higher of the yeast-based protein source, reductions (P < 0.05) in weight gain were observed. A subsequent trial utilizing diets containing 50 and 75% of the yeast-based protein source in place of fishmeal with supplemental amino acids (methionine, 0.3% of dry diet; tryptophan, 0.2% of dry diet and taurine, 0.5% of dry diet) showed improved weight gain and feed efficiency ratio values, but only when taurine was supplemented at 0.5% of dry diet. A final trial was conducted to verify these findings, again using 50 and 75% replacement of fish meal with the yeast-based protein source and only taurine as the supplemental amino acid (0.5% of dry diet) and identical results were obtained. Thus, cobias fed diets containing 50 and 75% of the yeast-based protein source with supplemental taurine, in place of fish meal, performed equally or better than fish fed the fish meal-based control diet.