饲粮支链氨基酸比例对28~63日龄攸县麻鸭肠道菌群的影响

Effect of Dietary Branched-chain Amino Acid Ratio on Intestinal Flora of 28-63 Days Old Youxian Duck

本文旨在研究不同比例支链氨基酸(BCAAs)对28~63日龄攸县麻鸭盲肠微生物菌群的影响。采用单因子设计,选用28日龄健康、体质量相近的攸县麻鸭504羽,随机分为6个处理,每处理6个重复,每重复14羽,分别饲喂不同比例支链氨基酸(BCAAs)饲粮。其中BCAAs饲粮中亮氨酸、缬氨酸、异亮氨酸按质量比m(Leu)∶m(Val)∶m(Ile)分为1∶0.4∶0.3(MA组)、1∶0.5∶0.4(MB组)、1∶0.6∶0.5(MC组)、1∶0.7∶0.6(MD组)、1∶0.8∶0.7(ME组)和1∶0.9∶0.8(MF组)共6组。试验期35 d,试验结束当天,分别从每重复中选择1羽试鸭采集盲肠内容物,利用16S rDNA测序技术分析盲肠微生物结构和菌群多样性。结果显示:1)6个组共有的OTU数目344,仅MD组存在1个特有的OTU。2)在门水平上,核心菌群是拟杆菌门Bacteroidetes、厚壁菌门Firmicute和变形菌门Proteobacteria;在属水平上,拟杆菌属Bacteroides和脱硫弧菌属Desulfovibrio为优势菌属。3)6组比较发现,MD组变形菌门丰度显著高于ME组(P<0.05),MF组放线菌门丰度显著高于MA组(P<0.05)。4)6个试验组间Ace指数和Chao1指数的差异不显著,MF组的Shannon指数显著大于MC组(P<0.05),MC组的Simpson指数极显著大于MF组(P<0.01)和显著大于MA组(P<0.05)。综上,63日龄攸县麻鸭盲肠的核心菌群是拟杆菌门、厚壁菌门、变形菌门,饲粮BCAAs比例显著影响变形菌门及放线菌门,当m(Leu)∶m(Val)∶m(Ile)=1∶0.9∶0.8时,攸县麻鸭盲肠微生物物种多样性最高。

A single factor experiment was adopted to investigate the effects of dietary branched-chain Amino Acid ratio flora of 28-63 days old Youxian duck.504 Youxian ducks of 28 day-old and healthy and similar in weight were randomly allocated to 6 groups with 6 replicates each group and 14 in each replicate.Six diets with leucine,valine and isoleucine ratios of 1∶0.4∶0.3(group MA),1∶0.5∶0.4(group MB),1∶0.6∶0.5(group MC),1∶0.7∶0.6(group MD),1∶0.8∶0.7(group ME)and 1∶0.9∶0.8(group MF)were avilable.The experiment lasted for 35 days.At the end of the feeding experiment,one duck was selected from each replicate of each treatment to collect cecal contents,and the cecal microbial structure and flora diversity were detected and analyzed by 16S rDNA sequencing technology.The results show that:1)There are 344 identical OTUs in the 6 groups,and only one unique OTU existed in group MD.2)At the phylum level,the core flora are Bacteroidetes,Firmicutes and Proteobacteria.At the genus level,Bacteroides and Desulfovibrio are the dominant genera;3)The results of comparion among the 6 groups show that,the abundance of Proteobacteria in group MD is significantly higher than that in group ME(P<0.05),and the abundance of Actinomycetes in group MF is significantly higher than that in group MA(P<0.05);4)There is no significant difference in Ace index and Chao1 index among the 6 groups,however,the Shannon index in group MF is significantly higher than that in group MC(P<0.05),and Simpson index in group MC is significantly higher than that in group MF(P<0.01)and significantly higher than that in group MA(P<0.05).In summary,the core flora of the cecum of 63-day-old Youxian duck is Bacteroides,Firmicutes,and Proteobacteria.The proportion of branched-chain amino acids in diets significantly affects the Proteobacteria and Actinomycetes.When the ratio of mleucine,valine and isoleucine is 1∶0.9∶0.8,the microbial species diversity of the cecum in Youxian duck is the highest.