Desempenho e qualidade da carcaça e do filé de Tilápias (Oreochromis niloticus) alimentadas com dietas contendo ractopamina

Abstract

The use of food additives, especially carcass enhancers, in animal production is increasing and further studies must be conducted so that its effects may be determined with better precision. This study aimed at evaluating the performance and the quality of the fillet of tilapia (Oreochromis niloticus) fed diets containing different levels of ractopamine (0, 10, 15, 20 and 30 ppm). The zootechnical parameters observed were: average daily weight gain, feed conversion, protein efficiency rate, carcass yield, and fillet, in which only the first three presented significant differences (P <0.05), however little expressive. Regarding the fillet quality, the following analyzes were performed: bromatology, shearing force, weight loss, pH, color and lipid oxidation. Humidity, ash and crude protein showed significant differences (P <0.05), such as the weight losses during thawing and baking. The pH, after 24 hours of slaughtering the fish, also showed expressive differences (P <0.05). By observing these results assembled, the ractopamine administered in the tilapia ration may be a beneficial option for moderate improvement of some fillet characteristics. The levels of ractopamine which presented the best results were around 15ppm, concluding this as the best level to be used, while for superior values, ractopanime use is not justified.