Restrição alimentar para juvenis de Tilápia do Nilo

Abstract

This study aimed to evaluated of diferente restriction strategies on the development of juvenile Nile tilapia. 160 fish were used (3,23 ± 0,07 g), distributed in 20 plastic mesh bags arranged in a concrete tank in a system with constant aeration by central air blower. The experimental design was completely randomized with four treatments and five repetitions. The treatments consisted of 7:0 – fed daily; 6:1 – fed six days followed by a day of food restriction; 5:2 – fed five days followed by two days of foood restriction and 1:1 – fed one day, followed by one day of restriction to feed. The commercial feed used had 33.70% of crude protein, and the fish were fed four times a day until apparent satiety for a period of 60 days. At the end of the experimental period, significant differences were observed between the diferente dietary restrictions (P<0,05) for final weight, weight gain, final length, hepatossomatic index, visceral fat, intestinal quocient, specific growth rare, in frequency of muscle fibers in the class < 20 μm and between 20 and 50 μm. The intestinal villus height did not differ (P>0,05) between treatments. The frequent supply of food (7:0) provided greater growth in relation to treatment 1:1 (interspeced). However, for the same restriction, the frequent supply of food (7:0) did not differ in the diameter classes of muscle fibers frequency and intestinal villus, providing intense muscular hyperplasia, characteristic of this juvenile phase. Therefore, it is concluded that the food restriction for Nile tilapia juveniles influence the performance and muscle growth, and this practice is not recommended for this development stage.