Effects of Supplementation of Bacillus subtilis and β-Glucan in Cottonseed Protein Concentrate Diets on Growth Performance,Serum Biochemical Indices and Organismal Health of Juvenile Rainbow Trout(Oncorhynchus mykiss)
This experiment was conducted to investigate the effects of supplementation of Bacillus subtilis andβ-glucan in cottonseed protein concentrate diets on growth performance,serum biochemical indices and organ-ismal health of juvenile rainbow trout(Oncorhynchus my kiss).A total of 420 healthy juvenile rainbow trout with similar body weight of(21.66±0.08)g were randomly divided into 7 groups with 3 replicates per group and 20 trout per replicate.The control group(CON group)was fed the basal diet,the cottonseed protein con-centrate group(CPC group)was fed the diet with 30％cottonseed protein concentrate equal to replace the fish meal in the basal diet,and the experimental groups were supplemented with 1×106 CFU/g Bacillus subtilis(group Ⅰ),1×108 CFU/g Bacillus subtilis(group Ⅱ),1×108 CFU/g Bacillus subtilis lyophilized powder(group Ⅲ)and 0.1％(group Ⅳ)and 1.0％β-glucan(group Ⅴ)in the diets of CPC group,respectively.The experiment lasted for 8 weeks.The results showed as follows:1)compared with CON group,the final body weight,weight gain rate(WGR)and specific growth rate(SGR)of juvenile rainbow trout in CPC group and experimental groups were significantly decreased(P＜0.05),while the feed coefficient(FCR)was significantly increased(P＜0.05);compared with CPC group,there were no significant differences in growth performance indices in experimental groups(P＞0.05).2)Compared with CON group,the serum glutamic-pyruvic transaminase(ALT)activity in CPC group was significantly increased(P＜0.05);compared with CPC group,the serum ALT activity in experimental groups was significantly decreased except group Ⅲ(P＜0.05);the serum lysozyme(LSZ)activity in experimental groups was significantly higher than that in CON and CPC groups(P＜0.05).3)Compared with CON group,the intestinal lipase and α-amylase activities of juvenile rainbow trout in CPC group were significantly decreased(P＜0.05);compared with CPC group,the intestinal lipase activity in experimental groups was significantly increased(P＜0.05),and the intestinal α-am-ylase activity in groups Ⅰ and Ⅱ was significantly increased(P＜0.05).4)Compared with CON group,the intestinal total antioxidant capacity(T-AOC)and catalase(CAT)activity of juvenile rainbow trout in CPC group were significantly decreased(P＜0.05),while the intestinal malondialdehyde(MDA)content was sig-nificantly increased(P＜0.05);compared with CPC group,the intestinal T-AOC and CAT activity in experi-mental groups were significantly increased(P＜0.05),and the intestinal MDA content in groups Ⅱ,Ⅲ and Ⅴwas significantly decreased(P＜0.05).5)Compared with CON group,the mRNA relative expression levels of intestinal interleukin-1 β(IL-1β),interleukin-8(IL-8)and tumor necrosis factor-α(TNF-α)of juvenile rain-bow trout in CPC group were significantly increased(P＜0.05),while the mRNA relative expression levels of intestinal transforming growth factor-β(TGF-β)and interleukin-10(IL-10)were significantly decreased(P＜0.05);compared with CPC group,the mRNA relative expression levels of intestinal IL-1β,IL-8 and TNF-αmRNA in experimental groups were significantly decreased(P＜0.05),the intestinal TGF-β mRNA relative expression level in experimental groups was significantly increased except group Ⅳ(P＜0.05),and the intesti-nal IL-10 mRNA relative expression level in groups Ⅱ and V was significantly increased(P＜0.05).6)Com-pared with CON group,the mRNA relative expression levels of intestinal claudin-1(CLD1),occludin(OCLN),tricellulin(TRIC)and zonula occludens-1(ZO-1)as well as complement 3(C3)and complement 4(C4)of juvenile rainbow trout in CPC group were significantly decreased(P＜0.05);compared with CPC group,the mRNA relative expression levels of intestinal OCLN,TRIC,ZO-1,C3 and C4 in experimental groups were significantly increased except group Ⅳ(P＜0.05).7)Compared with CON group,the intestinal villus height of juvenile rainbow trout in CPC group was significantly decreased(P＜0.05);compared with CPC group,the intestinal villus height in groups Ⅰ to Ⅲ was significantly increased(P＜0.05),and the intes-tinal muscular thickness in group Ⅱ was significantly increased(P＜0.05).8)Compared with CON group,the Aeromonas salmonicida number in liver and spleen of juvenile rainbow trout in CPC group was significantly increased(P＜0.05);compared with CPC group,except group Ⅳ,Aeromonas salmonicida number in liver in experimental groups was significantly decreased(P＜0.05),and Aeromonas salmonicida number in spleen in experimental groups was significantly decreased(P＜0.05).In conclusion,the supplementation of Bacillus subtilis and β-glucan in cottonseed protein concentrate diets has no significant effects on the growth perform-ance of juvenile rainbow trout,but can improve the serum biochemical indices,intestinal health and the ability to resist Aeromonas salmonicida.In addition,the spray process of adding 1×108 CFU/g Bacillus subtilis and adding 1.0％β-glucan have better effects on juvenile rainbow trout.[Chinese Journal of Animal Nutrition,2024,36(6):3857-3875]
Oncorhynchus mykisscottonseed protein concentrateBacillus subtilisβ-glutengrowth per-formanceintestinal health
万方数据
维普
