饲粮粗蛋白质水平对育成期蛋鸡肠道形态、盲肠菌群结构及肠道屏障的影响

Effects of Dietary Crude Protein Level on Intestinal Morphology,Cecal Microflora Structure and Intestinal Barrier of Laying Hens During Growing Period

试验旨在研究饲粮粗蛋白质水平对育成期蛋鸡肠道形态、盲肠微生物组成及其代谢产物生物胺及肠道黏膜屏障功能的影响。将180只14周龄罗曼育成期蛋鸡分为3组:15.5%粗蛋白质组(15.5%CP组)、14.5%粗蛋白质组(14.5%CP组)、13.5%粗蛋白质组(13.5%CP组)。每组6个重复,每个重复10只鸡,预试期7 d,正试期21 d。结果显示:与15.5%CP组相比,13.5%CP组十二指肠和回肠的绒毛长度(VH)与绒隐比(V/D)显著增加(P<0.05),而隐窝深度(CD)显著下降(P<0.05);与15.5%CP组相比,13.5%CP组生物胺含量、炎性因子相关基因NF-κB和LITAF mRNA表达量显著下调(P<0.05),而肠黏膜屏障相关基因Claudin-1、MUC2和ZO-1 mRNA表达量显著上调(P<0.05)。饲粮粗蛋白质水平对盲肠微生物区系alpha多样性具有显著影响(P<0.05),而对门、科水平上的微生物区系组成的影响不显著(P>0.05)。综上所述,饲粮低蛋白水平促进育成期蛋鸡绒毛发育,增加肠黏膜屏障相关因子的表达,同时降低肠道生物胺含量和抑制炎性相关因子的表达,从而调控肠黏膜屏障健康。

This experiment was conducted to investigate the effects of dietary crude protein level on intestinal morphology,cecal microbial composition and its metabolites bioamines and mucosal barrier function of laying hens during growing period.One hundred and eighty 14-week-old Roman laying hens were divided into three groups:15.5%crude protein group(15.5%CP group),14.5%crude protein group(14.5%CP group)and 13.5%crude protein group(13.5%CP group).Each group had 6 replicates with 10 chickens per replicate.The pre-experiment lasted for 1 week and the experiment lasted for 3 weeks.The results showed that compared with 15.5%CP group,villus length(VH)and villus height/crypt depth(V/D)of duodenum and ileum in13.5%CP group were significantly increased(P<0.05),while crypt depth(CD)was significantly decreased(P<0.05);Compared with 15.5%CP group,biogenic amino content and mRNA expression levels of NF-κB and LITAF related inflammatory factors were significantly down-regulated in 13.5%CP group(P<0.05),while mRNA expression levels of claudin-1,MUC2 and ZO-1 related intestinal mucosal barrier genes were significantly up-regulated(P<0.05).Microbial 16S RNA analysis showed that dietary crude protein level significantly affected the alpha diversity of cecum microflora(P<0.05),but had no significant effect on the microflora structure at phylum and family level(P>0.05).In conclusion,dietary low protein level could promote the development of villus in laying hens during growing period,increase the expression of intestinal mucosal barrier-related factors,reduce the content of intestinal biogenic amines and inhibit the expression of inflammatory-related factors,thereby regulate the health of the intestinal mucosal barrier.