흰다리새우(Litopenaeus vannamei)의 저어분 사료 내 가수분해 효모가 성장 및 면역에 미치는 영향

Abstract

An eight-week feeding trail was performed to evaluate the effects of yeast hydrolysate (YH) supplementation in a low-fishmeal diet on growth, immune responses, intestinal histology and disease resistance of whiteleg shrimp (Litopenaeus vannamei). Five experimental diets were prepared by supplementing YH at 0 (CON), 5 (YH5), 10 (YH10), 20 (YH20) and 40 (YH40) g/kg to a basal diet containing 10% fishmeal and compared with a positive control with 25% fishmeal (FM25). Shrimp with an initial average weight of 0.43 ± 0.005 g (mean ± SD) were stocked in 18 tanks (each diet three replicates) with a stocking density of 20 shrimp per tank and fed the experimental diets four times a day at apparent satiation. Results showed that shrimp fed the FM25 diet exhibited significantly higher final body weight, weight gain, specific growth rate and protein efficiency ratio than those fed CON, YH5, YH10 and YH20 diets (P < 0.05). However, there were no significant differences between shrimp fed the YH40 and FM25 diets (P > 0.05). In addition, there were no significant differences in whole-body proximate composition, hemolymph biochemical parameters and non-specific immune responses among treatments (P > 0.05). Intestinal villi length and muscular layer thickness of shrimp fed the YH40 and FM25 diets were significantly higher than the other groups (P < 0.05). At the end of bacterial (Vibrio parahaemolyticus) challenge test, shrimp fed YH40 and FM25 diets showed a significantly higher survival rate than those of shrimp fed CON, YH5 and YH10 (P < 0.05). These results suggest that supplementing 4% YH in diet containing 10% fishmeal could beneficially influence growth, intestinal morphology, and disease resistance of whiteleg shrimp.