摘要
本试验旨在研究饲料中添加枯草芽孢杆菌对大口黑鲈幼鱼生长、肠道组织结构、抗氧化能力、免疫能力和肠炎的影响。试验设置3个组(对照组,饲喂基础饲料;0.5%枯草芽孢杆菌组,饲喂基础饲料+0.5%枯草芽孢杆菌制剂;1.0%枯草芽孢杆菌组,饲喂基础饲料+1.0%枯草芽孢杆菌制剂),每组设置3个重复,每个重复20尾鱼,对初始体重为(16.0±0.5)g的大口黑鲈幼鱼开展6周的投喂试验。结果表明:1)饲喂6周后,枯草芽孢杆菌组大口黑鲈幼鱼的增重率、特定生长率、体重均高于对照组,但没有显著差异(P>0.05)。2)在注射2,4,6-三硝基苯磺酸(TNBS)诱导肠炎后,各组大口黑鲈均发生死亡情况,但添加枯草芽孢杆菌降低了累积死亡率。3)添加枯草芽孢杆菌后大口黑鲈幼鱼中肠绒毛纤长紧密、排列整齐,肠绒毛高度和数量以及肌层厚度较对照组显著增加(P<0.05)。TNBS诱导的肠炎损害了以绒毛融合、黏膜下层增宽和肌层为特征的肠道结构,但添加枯草芽孢杆菌明显减轻了TNBS对后肠的损害。4)大口黑鲈幼鱼肠道抗氧化酶活性均随饲料中枯草芽孢杆菌添加量的提高而上升,其中1.0%枯草芽孢杆菌组肠道总超氧化物歧化酶(T-SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性显著高于对照组和0.5%枯草芽孢杆菌组(P<0.05),丙二醛(MDA)含量显著低于对照组(P<0.05)。肠炎可提高大口黑鲈幼鱼肠道中抗氧化酶活性,且添加枯草芽孢杆菌后大口黑鲈幼鱼肠道的抗氧化能力更强。5)大口黑鲈幼鱼肠道酸性磷酸酶(ACP)、溶菌酶(LZM)活性随着枯草芽孢杆菌添加量的增加显著升高(P<0.05),1.0%枯草芽孢杆菌组肠道碱性磷酸酶(AKP)活性显著高于对照组与0.5%枯草芽孢杆菌组(P<0.05)。经注射TNBS诱导肠炎后,3组大口黑鲈幼鱼肠道免疫酶活性均显著升高(P<0.05),且1.0%枯草芽孢杆菌组大口黑鲈肠道ACP、AKP、LZM活性均显著高于对照组(P<0.05)。6)与对照组相比,添加0.5%或1.0%枯草芽孢杆菌均能显著降低肠道促炎因子白细胞介素-1β(IL-1β)、白细胞介素-15(IL-15)、肿瘤坏死因子-α(TNF-α)和白细胞介素-8(IL-8)的mRNA相对表达量,显著升高抗炎因子白细胞介素-10(IL-10)、转化生长因子-β1(TGF-β1)的mRNA相对表达量(P<0.05)。综上可知,饲料中添加枯草芽孢杆菌可提高大口黑鲈幼鱼的肠道抗氧化能力和免疫能力,并缓解由TNBS引起的肠道促炎因子的表达,以1.0%的添加量效果较好。
This experiment was conducted to investigate the effects of dietary Bacillus subtilis on the growth,intestinal tissue structure,antioxidant capacity,immunity and enteritis of juvenile largemouth bass(Micropterus salmoides).Three groups were set up to carry the feeding trial for 6 weeks,and they were control group(a basal diet),0.5%Bacillus subtilis group(the basal diet+0.5%Bacillus subtilis preparation)and 1.0%Bacillus subtilis group(the basal diet+1.0%Bacillus subtilis preparation).Each group had three replicates and each replicate had 20 fish with the initial body weight of(16.0±0.5)g.The results showed as follows:1)compared with control group,the weight gain rate(WGR),specific growth rate(SGR)and body weight after 6weeks in Bacillus subtilis groups were increased,but the differences were not significant(P>0.05).2)After injection of trinitro-benzene-sulfonic acid(TNBS)to induce enteritis,experimental fish in all group showed a certain mortality,but the addition of Bacillus subtilis reduced the cumulative mortality.3)After the addition of Bacillus subtilis,the midgut villi of largemouth bass were slender,closely arranged,and the height and number of intestinal villi and the thickness of muscle layer were significantly increased compared with the control group(P<0.05).TNBS induced enteritis damaged the intestinal structure characterized by villous fusion,submucosa widening and muscle layer,but the addition of Bacillus subtilis obviously reduced the damage.4)With the increase of dietary Bacillus subtilis supplemental level,the activities of antioxidant enzymes in the intestine showed an upward trend.The activities of total superoxide dismutase(T-SOD),catalase(CAT)and glutathione peroxidase(GSH-Px)in the intestine in 1.0%Bacillus subtilis group were significantly higher than those in control group and 0.5%Bacillus subtilis group(P<0.05),and the malondialdehyde(MDA)content was significantly lower than that in control group(P<0.05).Enteritis could improve the activities of antioxidant enzymes in the intestine of juvenile largemouth bass,and the intestinal antioxidant capacity of juvenile largemouth bass was stronger after adding Bacillus subtilis.5)The activities of acid phosphatase(ACP)and lysozyme(LZM)in the intestine were significantly increased with the increase of Bacillus subtilis supplemental level(P<0.05).The activity of alkaline phosphatase(AKP)in the intestine in 1.0%Bacillus subtilis group was significantly higher than that in control group and 0.5%Bacillus subtilis group(P<0.05).After enteritis was induced by TNBS,the intestinal immune enzyme activities of the three groups were significantly increased(P<0.05),and the intestinal ACP,AKP and LZM activities in 1.0%Bacillus subtilis group were significantly higher than those in control group(P<0.05).6)Compared with the control group,the addition of 0.5%or 1.0%Bacillus subtilis could significantly reduce the mRNA relative expression levels of intestinal proinflammatory factors such as interleukin-1β(IL-1β),interleukin-15(IL-15),tumor necrosis factor-α(TNF-α)and interleukin-8(IL-8),and significantly increase the mRNA relative expression levels of anti-inflammatory factors such as interleukin-10(IL-10)and transforming growth factor-β1(TGF-β1)(P<0.05).To sum up,the addition of Bacillus subtilis in the diet can improve the intestinal antioxidant capacity and immunity of juvenile largemouth bass,and alleviate the intestinal injury caused by TNBS.The effect is better with the addition of 1.0%.
作者
张冬梅
颜浩骁
罗茂林
杨懿
胡一帆
龚晨昕
李志琼
杨淞
赵柳兰
ZHANG Dongmei;YAN Haoxiao;LUO Maolin;YANG Yi;HU Yifan;GONG Chenxin;LI Zhiqiong;YANG Song;ZHAO Liulan(College of Animal Science and Technology,Sichuan Agricultural University,Chengdu 611130,China;Sichuan Tequ Investment Group Co.,Ltd.,Chengdu 611430,China)
出处
《动物营养学报》
CAS
CSCD
北大核心
2022年第1期575-588,共14页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家自然科学基金项目(31802267)
四川农业大学双支计划(1921993232)。
关键词
枯草芽孢杆菌
大口黑鲈
生长
肠道组织结构
抗氧化酶
免疫酶
肠炎
Bacillus subtilis
largemouth bass
growth
intestinal tissue structure
antioxidant enzyme
immune enzyme
enteritis
