Acid fish silage in the diet of pacu and tambacu reared at cold suboptimal temperature

Abstract: The objective of this work was to evaluate the supplementation of diet of pacu and tambacu with acid fish silage during winter. The experimental design was a 2 × 2 factorial arrangement (two genetic groups and two diets), with three replicates. The genetic group factor was composed of pacu (Piaractus mesopotamicus) and tambacu (♀ Colossoma macropomum × ♂ Piaractus mesopotamicus). The two diets were based on plant ingredients; one of them was supplemented with acid fish silage (silage diet), and the other was a base diet without supplementation. Twelve net tanks, six from which with pacu, and six with tambacu, were used as experimental units, with ten fish in each tank. There was an interaction of the factors for final length, final weight, and daily weight gain. Pacu fed the silage diet showed a higher growth than pacu fed with the base diet; however, this effect was not observed for tambacu. A higher feed efficiency was observed for pacu than for tambacu, without a diet effect. The diet supplementation with acid fish silage improves the productive performance of pacu reared at cold suboptimal temperature, but it does not have this effect on tambacu.

摘要：本研究旨在评估冬季期间，向短盖肥脂鲤 (pacu，*Piaractus mesopotamicus*) 与坦巴基杂交鲷 (tambacu，♀Colossoma macropomum × ♂Piaractus mesopotamicus) 的基础日粮中添加酸性鱼青贮料的饲喂效果。试验采用2×2因子设计（2个遗传组与2种日粮），设置3个重复。遗传组因子包含pacu与tambacu两类；两种日粮均以植物性原料为基础，其中一种添加酸性鱼青贮料（青贮日粮组），另一种为未添加的基础日粮组。本试验共使用12个网箱作为试验单元，其中6个用于养殖pacu，剩余6个用于养殖tambacu，每个网箱放养10尾试验鱼。因子交互作用对终末体长、终末体重及日增重均存在显著影响。饲喂青贮日粮的pacu生长性能优于饲喂基础日粮的pacu，但该效应未在tambacu中观测到。pacu的饲料效率高于tambacu，且不受日粮类型的影响。在低温亚适宜温度下养殖的pacu，日粮添加酸性鱼青贮料可改善其生产性能，但对tambacu无此正向效果。