Total Sulfur Amino Acid Requirement of Tilapia: a Review and Application to Practical Diets

Tilapia is fast becoming one of the most important farmed fish species. Since protein is one of the most expensive components of tilapia feeds, its utilization must be optimized and the cost minimized. The development of commercial feeds for tilapia has been traditionally based on the use of fish meal as the main protein source. However, the limited supply coupled with an increasing demand from the animal feed industry result in a high price for this ingredient. Thus it is critical that tilapia feed industry reduce its reliance on fish meal. Quite often, methionine is one of the most limiting amino acids in non-fish meal protein sources used to formulate commercial tilapia feeds. In order to maximize the utilization of these protein sources, methionine requirement must be precisely determined. A series of studies have been conducted to evaluate the possibility of using alternative plant and animal protein sources to replace fish meal in practical diets, as well as determine the TSAA requirement and replacement value of cystine for methionine in semi-purified diets and apply these research findings to practical diets for juvenile tilapia.