Effects of dietary synbiotics supplementation methods on growth, intestinal health, non-specific immunity and disease resistance of Pacific white shrimp, Litopenaeus vannamei.

ABSTRACT The present study aims to investigate the effects of dietary synbiotics supplementation methods on growth, feed utilization, hepatopancreas and intestinal histology, non-specific immunity and microbiota community of Pacific white shrimp (Litopenaeus vannamei). A control diet was designed to contain 18% fish meal (CON), and then 3 g kg-1 synbiotics (Bioture, consisting of Bacillus subtilis, Saccharomyces cerevisiae, β-glucan and mannan oligosaccharide, etc) was supplemented to the control diet with three methods, directly adding in diets for pelleting (DAP), spraying diets after pelleting at once (SDA), spraying diets before feeding every day (SDE). Shrimp with initial body weight of 1.5 ± 0.12 g were fed one of the four diets for 56 days. The results showed that dietary synbiotics significantly increased the weight gain (WG), apparent digestibility coefficient (ADC) of crude protein (CP) and dry matter (DM), hepatopancreatic protease activity and decreased feed conversion ratio (FCR) (P