Effect of dietary supplementation of methionine and/or lysine on growth performance and body composition of tilapia nilotica fingerlings

ABSTRACT

An experiment was conducted to evaluate the growth performance and body composition of Tilapia nilotica fingerlings fed diets supplemented with methionine and /or lysine at different levels. A total of 216 Tilapia nilotica of nearly similar weight [22 g] were allotted into 9 groups. Fish meal, soybean oil meal, ground yellow corn, wheat bran, cottonseed oil, carboxymethyl cellulose, mineral mixture and vitamin mixture were used to formulate a balanced basal diet. Methionine and lysine were supplemented in percentages of 0.0 + 0.0, 0.27 + 0.0, 0.54 + 0.0, 0.0 + 0.81, 0.0 + 1.62, 0.27 + 0.81, 0.27 + 1.62, 0.54 + 0.81, 0.54 + 1.62 to the diets 1 to 9, respectively. Fish of groups 2 to 9 which were fed on diets supplemented with methionine and /or lysine at different levels achieved the best values of the tested performance parameters [total and weekly body weight gain, SGR, FCR, PER, increase in length and condition factor] when compared to group 1 [control group] which was fed on the basal diet without any supplementation. The average dressing% and organoleptic characteristic score did not differ significantly between fish groups. The proximate fish body composition was not greatly affected by any dietary treatment. Retention of dry matter, crude protein and ash in fish of groups 2 to 9 showed the highest values when compared to those of group 1 [control group]. It can be concluded that supplementation of methionine and /or lysine to ordinary diets significantly improves the growth performance and nutrient retention of Tilapia nilotica