棉籽浓缩蛋白饲料添加枯草芽孢杆菌和β-葡聚糖对虹鳟幼鱼生长性能、血清生化指标和机体健康的影响

Effects of Supplementation of Bacillus subtilis andβ-Glucan in Cottonseed Protein Concentrate Diets on Growth Performance,Serum Biochemical Indices and Organismal Health of Juvenile Rainbow Trout(Oncorhynchus mykiss)

本试验旨在探究在棉籽浓缩蛋白饲料中添加枯草芽孢杆菌和β-葡聚糖对虹鳟幼鱼生长性能、血清生化指标和机体健康的影响。试验选择体质量[(21.66±0.08)g]基本一致的健康虹鳟幼鱼420尾,随机分为7组,每组3个重复,每个重复20尾。对照组(CON组)饲喂基础饲料,棉籽浓缩蛋白组(CPC组)饲喂用30%棉籽浓缩蛋白等量替代基础饲料中鱼粉的饲料,试验组分别在CPC组饲料的基础上添加1×10^(6)CFU/g枯草芽孢杆菌(Ⅰ组)、1×10^(8)CFU/g枯草芽孢杆菌(Ⅱ组)、1×10^(8)CFU/g枯草芽孢杆菌冻干粉(Ⅲ组)以及在CPC组饲料中添加0.1%(Ⅳ组)和1.0%β-葡聚糖(Ⅴ组)。试验期8周。结果表明:1)与CON组相比,CPC组和各试验组虹鳟幼鱼终末体质量、增重率(WGR)和特定生长率(SGR)均显著降低(P<0.05),饲料系数(FCR)均显著提高(P<0.05);与CPC组相比,各试验组生长性能指标均无显著差异(P>0.05)。2)与CON组相比,CPC组血清谷丙转氨酶(ALT)活性显著提高(P<0.05);与CPC组相比,除Ⅲ组外,其他试验组血清ALT活性均显著降低(P<0.05);各试验组血清溶菌酶(LSZ)活性均显著高于CON组和CPC组(P<0.05)。3)与CON组相比,CPC组虹鳟幼鱼肠道脂肪酶和α-淀粉酶活性显著降低(P<0.05);与CPC组相比,各试验组肠道脂肪酶活性均显著提高(P<0.05),Ⅰ组和Ⅱ组肠道α-淀粉酶活性显著提高(P<0.05)。4)与CON组相比,CPC组虹鳟幼鱼肠道总抗氧化能力(T-AOC)和过氧化氢酶(CAT)活性显著降低(P<0.05),肠道丙二醛(MDA)含量显著提高(P<0.05);与CPC组相比,各试验组肠道T-AOC和CAT活性显著提高(P<0.05),Ⅱ组、Ⅲ组和Ⅴ组肠道MDA含量显著降低(P<0.05)。5)与CON组相比,CPC组虹鳟幼鱼肠道白细胞介素-1β(IL-1β)、白细胞介素-8(IL-8)和肿瘤坏死因子-α(TNF-α)mRNA相对表达量显著提高(P<0.05),肠道转化生长因子-β(TGF-β)和白细胞介素-10(IL-10)mRNA相对表达量显著降低(P<0.05);与CPC组相比,各试验组肠道IL-1β、IL-8和TNF-αmRNA相对表达量均显著降低(P<0.05),除Ⅳ组外,其他试验组肠道TGF-βmRNA相对表达量均显著提高(P<0.05),Ⅱ组和Ⅴ组肠道IL-10 mRNA相对表达量显著提高(P<0.05)。6)与CON组相比,CPC组虹鳟幼鱼肠道封闭蛋白-1(CLD1)、闭合蛋白(OCLN)、三细胞紧密连接蛋白(TRIC)和闭锁小带蛋白-1(ZO-1)以及补体3(C3)和补体4(C4)mRNA相对表达量均显著降低(P<0.05);与CPC组相比,除Ⅳ组外,其他试验组肠道OCLN、TRIC和ZO-1以及C3和C4 mRNA相对表达量均显著提高(P<0.05)。7)与CON组相比,CPC组虹鳟幼鱼肠道绒毛高度显著降低(P<0.05);与CPC组相比,Ⅰ组~Ⅲ组肠道绒毛高度显著提高(P<0.05),且Ⅱ组肠道肌层厚度显著提高(P<0.05)。8)与CON组相比,CPC组虹鳟幼鱼肝脏和脾脏杀鲑气单胞菌数量显著提高(P<0.05);与CPC组相比,除Ⅳ组外,其他试验组肝脏鲑气单胞菌数量显著降低(P<0.05),各试验组脾脏杀鲑气单胞菌数量均显著降低(P<0.05)。综上所述,棉籽浓缩蛋白饲料添加枯草芽孢杆菌和β-葡聚糖对虹鳟幼鱼生长性能无显著影响,但改善了其血清生化指标、肠道健康和抗杀鲑气单胞菌能力,且以喷涂工艺添加1×10^(8)CFU/g枯草芽孢杆菌和添加1.0%β-葡聚糖对虹鳟幼鱼的效果较佳。

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 organismal health of juvenile rainbow trout(Oncorhynchus mykiss).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 concentrate 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 1×10^(6)CFU/g Bacillus subtilis(groupⅠ),1×10^(8)CFU/g Bacillus subtilis(groupⅡ),1×10^(8)CFU/g Bacillus subtilis lyophilized powder(groupⅢ)and 0.1%(groupⅣ)and 1.0%β-glucan(groupⅤ)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 groupⅢ(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 andα-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 intestinalα-amylase activity in groupsⅠandⅡwas 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 significantly increased(P<0.05);compared with CPC group,the intestinal T-AOC and CAT activity in experimental groups were significantly increased(P<0.05),and the intestinal MDA content in groupsⅡ,ⅢandⅤwas significantly decreased(P<0.05).5)Compared with CON group,the mRNA relative expression levels of intestinal interleukin-1β(IL-1β),interleukin-8(IL-8)and tumor necrosis factor-α(TNF-α)of juvenile rainbow 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-βmRNA relative expression level in experimental groups was significantly increased except groupⅣ(P<0.05),and the intestinal IL-10 mRNA relative expression level in groupsⅡandⅤwas significantly increased(P<0.05).6)Compared 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,C 3 and C 4 in experimental groups were significantly increased except groupⅣ(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 groupsⅠtoⅢwas significantly increased(P<0.05),and the intestinal muscular thickness in groupⅡwas 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 groupⅣ,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 andβ-glucan in cottonseed protein concentrate diets has no significant effects on the growth performance of juvenile rainbow trout,but can improve the serum biochemical indices,intestinal health and the ability to resist Aeromonas salmonicid a.In addition,the spray process of adding 1×10^(8)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]