高糖饲料对黄颡鱼生长及肠道菌群结构的影响

Effect of High Carbohydrate Diet on Growth and Gut Microbial Community Structure of Yellow Catfish(Pelteobagrus fulvidraco)

研究以淀粉为主要糖源制备高糖饲料对黄颡鱼(Pelteobagrus fulvidraco)生长和肠道菌群结构的影响。选用初始体重(4.13±0.11)g的黄颡鱼180尾,随机分为2组,每组设3个重复,每个重复30尾,对照组(CG)投喂糖水平23.25%的基础饲料;高糖组(HG)投喂糖水平31.11%的高糖饲料,两组实验料等氮等能(粗蛋白36.5%,能量16.1 kJ/g)。56 d的养殖实验表明:HG特定生长率和增重率显著低于CG(P<0.05);HG饲料系数高于CG,但与CG相比差异不显著(P>0.05)。HG肠道菌群系统发育多样性指数显著高于CG(P<0.05);OUT数量和Chao1指数低于CG,但差异不显著(P>0.05);Shannon和Simpson指数未体现显著差异(P>0.05)。变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes)为黄颡鱼的肠道优势菌门,HG肠道厚壁菌门相对丰度低于CG,拟杆菌门相对丰度高于CG,螺旋体门(Spirochaetes)相对丰度显著高于CG(P<0.05);HG梭菌属(Clostridium)和分节丝状菌属(Candidatus Arthromitus)菌群相对丰度显著低于CG(P<0.05),HG别样棒菌属(Allo-baculum)、普雷沃菌属(Prevotella)、棒状杆菌属(Corynebacterium)和密螺旋体属(Treponema)菌群相对丰度高于CG(P<0.05)。因此,长期摄入高糖饲料抑制了黄颡鱼生长,降低了饲料利用,同时改变了肠道菌群组成和结构,增加易感染疾病风险。

This experiment was conducted to investigate the effects of high carbohydrate diet on the growth and gut microbial community structure of Pelteobagrus fulvidraco.A total of 180 P.fulvidraco juveniles with initial body weight(4.13±0.11)g were randomly distributed into 2 groups with 3 replicates per group and 30 fish per replicate.The control group(CG)was fed with the diet of carbohydrate level 23.25%;the high carbohydrate group(HG)was fed with the diet of carbohydrate level 31.11%.Two dies were isonitrogenous and isoenergetic(crude protein level 36.5%and energy level 16.1 KJ/g).For 56-day feeding,the results showed that the specific growth rate and weight gain rate of HG were significantly lower than these of CG(P<0.05);the feed conversion rate HG was higher than that of CG,but no significant differences(P>0.05).The gut mi-croflora Phylogenetic diversity index of HG was significantly higher than that of CT(P<0.05);the OUT number and Chao1 indexes of HG were lower than these of CG,but no significant differences(P>0.05);there were no significant differences for Shannon and Simpson diversity index of the gut microflora(P>0.05).Proteobacteria,Firmicutes,Bacteroidetes and Actinobacteria were the dominant phyla in gut micro-bial community structure of P.fulvidraco.The relative abundance of Firmicutes of HG was lower than that of CG,the relative abundance of Bacteroidetes of HG was higher than that of CG,The relative abun-dance of Spirochaetes of HG was significantly higher than that of CG(P<0.05).The relative abundances of Clostridium and Candidatus Arthromitus of HG were significantly lower than these of CG(P<0.05).The relative abundances of Allobaculum,Prevotella,Corynebacterium and Treponema of HG were significantly higher than these of CG(P<0.05).Long-term intake of high carbohydrate diet inhibited the growth of P.fulvidraco;reduced the feed utilization;changed the composition and structure of the gut microflora and increased the risk of infection.