L-glutamina e L-glutamato em dietas para tilápias do Nilo (Oreochromis niloticus)

Abstract

Two studies were carried out to evaluate the dietary L-glutamine and L-glutamate in diets for Nile tilapia. It was utilized basal diet with supplemented with Aminogut®, source of L-glutamine and L-glutamate, in proportion of 0, 1, 2 and 3% of diet. In the first study, the juveniles Nile tilapia (27.76 ± 0.76 g) were distributed in cages of 0.12m3 in a randomized block design and four treatments with four replicates and fourteen fish per experimental unit. It was used a basal diet with 30% of crude protein and 2,980 kcal/kg of digestible energy and fish were fed to satiation during 47 days. In the second study, fingerlings Nile tilapias (0.60 ± 0.1 g) were distributed in tanks of 0.8m3 using a complete randomized experimental design with four treatments, three replicates and 90 fish per experimental unit. It was used a basal diet with 33% of crude protein and 2,940 kcal/kg of digestible energy and fish were fed to satiation during 85 days. The analyzed parameters in both experiments were: performance, carcass composition, villus height and blood ammonia and urea. In the first study, no effects were observed in fish fed with diets supplemented with L-glutamine and L-glutamate on performance, villus height and carcass composition. In the second study, feed intake, feed:gain ratio, protein efficiency ratio, nitrogen retention, hepatic somatic index, carcass composition and blood ammonia were not influence by L-glutamine and Lglutamate.It was observed a linear increase of L-glutamine and L-glutamate levels on weight gain. It was observed a quadratic effect of L-glutamine and L-glutamate levels on liver weight and villus height. It was concluded that the addition of L-glutamine and L- glutamate increase weight gain and villus height of Nile tilapia fingerlings.