后生元对工厂化循环水养殖美洲鳗鲡幼鱼生长及肠道健康的影响OA

This study aimed to investigate the effects of postbiotics on the growth and intestinal health of juvenile Anguilla rostrata reared in industrial recirculating aquaculture system.A total of 35 432 juvenile Anguilla rostrata with an initial weight of(10.88±0.75)g were selected and randomly divided into control group(group CON)and group LBC,with four replicates per group and 4 429 fish per replicate.The group CON was fed a basal diet,while the group LBC received a basal diet supplemented with 0.3%Lactobacillus and Bacillus licheniformis cultures(LBC).The pre-test period was three days,and the formal test period was 50 days.The results showed that compared with the group CON,the final weight,feed intake,weight gain rate,and specific growth rate in the group LBC were significantly increased(P＜0.05),the activities of intestinal catalase(CAT)and glutathione peroxidase(GSH-Px)were significantly increased(P＜0.05),and the content of malondialdehyde(MDA)was significantly reduced(P＜0.05).Histological analysis revealed that the addition of LBC increased the villus length in the foregut,midgut and hindgut,and increased the thickness of the foregut muscular layer and the villus density in the foregut and hindgut(P＜0.05).The addition of LBC significantly reduced Alpha diversity of gut microbiota(P＜0.05),and promoted the proliferation of beneficial bacteria.The study shows that adding 0.3%LBC to the feed can improve the growth performance and intestinal health of juvenile Anguilla rostrata reared in industrial recirculating aquaculture systems.