The ameliorative roles of dietary mannan oligosaccharides and vitamin E on growth performance, intestinal microbes, and structure, flesh quality, nutrient efficacy and stress resistance of pompano, Trachinotus ovatus

Abstract

The current study aimed to examine the effects of mannan oligosaccharides (MOS) and vitamin E (VE) on the growth, intestinal microorganisms, and structure, ammonia, and pathogen resistance of golden pompano, Trachinotus ovatus. Four diets were used: Control (un-supplementation), VE (0.01 % Vitamin E), MOS (0.4 % mannan oligosaccharide), and MOS+VE (0.40 %MOS+0.01 %VE) for 56-day. The results revealed a synergistic effect of MOS+VE on increments of growth rate of pompano. The total aerobic bacteria significantly increased in fish fed supplemented diets, with the highest counts was in fish fed MOS+VE. The Vibrio counts was significantly diminished in fish supplemented diets, with a minimal counts was in fish fed MOS+VE. Intestinal morphology (villus length, villus width, and villus surface area) of pompano fed MOS+VE and the mixture of MOS+VE significantly improved, with the best results observed in fish fed the combination (MOS+VE). Both MOS and VE enhanced protein and reduce lipid; however, fish fed combination (MOS+VE) had the highest performance in terms of protein content. The nutrient utilization (PER, PPV, LER and LPV) were significantly enhance in fish fed VE or MOS, but the highest of those values were in fish fed MOS+VE). Pompano can tolerate best against ammonia and pathogen, when supplemented with MOS and VE in their diet. The survival of fish fed MOS or VE were significantly higher under ammonia and pathogen infection, but insignificantly difference between them. It is recommended to add 4 g.kg−1 MOS and 0.1 g.kg−1 VE to the diet of pompano.