Desempenho produtivo, parâmetros sanguíneos e qualidade da carne de tilápias do Nilo alimentadas com dietas suplementadas com histidina e lisina

Abstract

Considering the growing demand for the inclusion of plant foods in tilapia diets, studies on the supplementation of lysine and histidine, potentially limiting amino acids and growth modulators for Nile tilapia in the finishing phase are important. Thus, the objective of this work was to evaluate the isolated or combined supplementation of histidine and lysine for Nile tilapia (Oreochromis niloticus) in the finishing phase, based on the productive performance, blood parameters and meat quality. An extruded diet was elaborated with 27.60% of crude protein and 3056.26 kcal / kg of digestible energy (Control). From the control diet, three diets supplemented with L-histidine (His), L-lysine (Lys) or blend of L-histidine and L-lysine (His+Lys) were prepared. Fish (n = 192; mean body weight = 136.14 ± 2.58 g) were distributed in a completely randomized design with four treatments and four replicates in 16 circular tanks of 600 L each. They were fed four times a day (8, 10, 13 and 15 hours) to apparent satiety. No effect (P <0.05) of diets with different histidine and lysine supplementation on the final weight, weight gain, hepatosomatic index, visceral fat, body amino acid composition, pH, yellow-blue color intensity, adhesiveness, meat chewability, and hematocrit, hemoglobin, cholesterol, and total protein blood parameters. Fish fed diets that received His supplementation and blend (His+Lys) presented better feed conversion (P = 0.001) than Control diet. Fillet yield, nitrogen retention, lysine body retention and plasma lysine levels were higher (P <0.001) for fish receiving diets Lys and the blend (His + Lys). Fish fed diets Lys and blend (His + Lys) presented lower (P <0.001) deposition of body lipids and triglyceride and glucose contents. Histidine retention and plasma levels were not influenced by treatments. The hardness variable of the tilapia fillets presented an effect (P = 0.001) for the fish that received the His, Lys and blend (His + Lys) diets, showing steeper fillets compared to the Control diet. The red - green color intensity (a *) was influenced by the diets (P = 0.021), where the fish fed with diets His and the blend (His + Lys) had lower values for meat coloration than the other diets. It was concluded that the combined supplementation of histidine and lysine improves the productive performance, reduces the deposition of body lipids, biochemical parameters such as triglyceride and glucose contents, improves plasma lysine concentration, fillet yield and meat quality of Nile tilapia in the termination.