EFFECTS OF LYSINE ON GROWTH OF TILAPIA FED DIETS RICH IN CORN GLUTEN MEAL

Tilapia is a warmwater fish with mild flavor. Nearly 8.6 million kg ar e produced domestically, and approximate to 22.7 million kg are import ed. Corn gluten meal (60% protein fraction) is a product obtained from wet-milling of corn. Diets (36% protein) containing 36-44% corn glute n meal with different levels of lysine and fish meal were formulated a nd fed to tilapia in aquaria for 12 weeks. Weight gain (WG) of tilapia fed diets containing the highest level of lysine (7.4% protein) with 4% fish meal was equal to that of fish fed a commercial control diet. Diets with lower lysine resulted in lower WG. The feed conversion rati o (FCR) and protein efficiency ratio (PER) of tilapia fed experimental diets containing adequate levels of essential amino acids and fish me al were the same as for fish fed the commercial control diet (also con taining fish meal). Fish fed diets containing lower lysine levels had less favorable FCR and PER. This study shows that corn gluten meal is utilized at high levels in tilapia diets, particularly if essential am ino acids are provided in adequate amounts.