Valuation of cottonseed meal in food of Nile tilapia (Oreochromis niloticus ?, L.) fingerlings

摘要

The experiment was carried out with the objective of evaluating the Nile tilapia fingerlings performance under different levels of cottonseed meal (CM) inclusion (0, 20, 40, 60 and 80%) with fiber and aminoacids correction. The experiment was carried out in the Laboratório de Aquicultura da Universidade Estadual de Maringá. Two hundred fifty fingerlings were used with an initial medium weight of 0.35 ± 0.07g, medium initial length of 2.95 ± 0.20cm, and an approximated age of 35 days. Fingerlings were divided in 25 tanks of 250 lt, in a completely randomized design with five treatments and five replications. The evaluated variables were weight gain (WG), feed gain (FG) , protein efficiency rate (PER), survival (S), hepatic-somatic index (HSI), condition factor (CF), protein in the carcass (PC), and fat in the carcass (FP). The WG and PER presented a linear decrease when the CM was included in the ration, as well FG and HSI. The S, DM, FC and CF did not show significant differences (P>0.05) among the treatments. It was concluded that cottonseed meal influenced in a negative way the fingerlings performance when the rations were supplemented with synthetic aminoacids.