The effects of methionine supplementation to soybean meal (SBM)-based diets on the growth and whole body-carcass chemical composition of tilapia (T. zillii)

The effects of supplementing soybean meal-based diets with methionine on the growth and carcass-whole body chemical composition of T. zillii were studied during a 62-day feeding trial. A control diet prepared for T. zillii was supplemented with five different levels of free methionine, 0.5%, 1%, 1.5%, 2% and 2.5% (the same amounts of ?-cellulose were removed). At the end of the study, the best growth rate and FCR were determined in the group fed a diet supplemented with 0.5% methionine (total 1.38% methionine+cystine). Statistically significant effects of methionine supplementation on whole body protein content were determined (p<0.05). No significant effects of control and test diets were detected on carcass dry matter and protein content; however, a significantly low (p