Methionine plus cystine to lysine ratio in diets for tambatinga fingerlings

ABSTRACT Among a variety of hybrids produced in Brazil, tambatinga is obtained from the crossing tambaqui female with pirapitinga male. Although rapid weight gain less time an attractive characteristic commercial viewpoint, information on its nutritional requirements, especially amino acid limited. As corn and soybean meal-based diets available for fish contain deficient levels essential methionine, our objective was to determine digestible methionine plus cystine lysine ratio fingerlings. We used 900 initial weights varying 1.49 ±0.59 4.14 ±1.70 g, they were fed six types different ratios (50, 55, 60, 65, 70, 75%). Performance parameters such as food efficiency, body depositions protein, fat, ash, nitrogen retention efficiency evaluated. The increase diet improved quadraticly feed intake, consumption cystine, gain, specific growth rate conversion, protein deposition ash until estimated 57%, 73%, 58%, 58% 59%, 60%, respectively; reduced linearly using gain. On other hand, fat not affected. concluded that cystine: rations fingerlings provide better performance deposition.