Protein Performance relation of commercials diets in the nile tilapia

Abstract

The study aims to evaluate the zootechnical performance of Nile tilapia fed with different commercial diets and relate such results with the centesimal composition and aminogram of the commercial feeds. There were five diets evaluated (A, B, C, D, and E) indicated for the tilapia growth-out phase (200 to 600g). Two hundred and twenty-five Nile tilapia (201.5 ± 4.7g) were distributed in 15 net tanks of 1m³ installed in ponds of 300m². After 98 days of rearing, the fish fed with diet E showed the best results, with final weight, fillet yield and feed conversion of up to 20% superior than other diets. Such a diet was the only one that reached values of the minimum requirement of tryptophan, besides showing an amino acid balance closer to the ideal protein for tilapia. The diet B showed crude protein values below the label (26%), as well as deficient in methionine, lysine and tryptophan, resulting in poor weight gain and feed conversion. The distance between the essential amino acid profile of diets and ideal profile for tilapia (DIP) showed a significant relation with the final weight and fillet yield. Therefore, it is concluded that the commercial diet with better amino acid balance, that is, a lower DPI shows the best performance.