聚乳酸对肉鸡生长性能和肠道功能的影响

Effects of Polylactic Acid on Growth Performance and Intestinal Function of Broiler Chickens

试验旨在研究聚乳酸(PLA)对AA肉鸡生长性能、肠道功能的影响。选取192只1日龄AA肉鸡随机分成4组,对照组饲喂基础饲粮,试验1、2、3组分别在基础饲粮中添加0.5%、1.0%、2.0%PLA,试验期42 d。分别于肉鸡21、42日龄测定了肉鸡生长性能、肠道屏障功能、肠道消化酶活性、小肠组织结构、小肠食糜pH和盲肠微生物。结果表明:①与对照组相比,1~21日龄时,1组平均日采食量(ADFI)显著升高(P<0.05),22~42日龄时,1、2组平均日增重(ADG)显著升高(P<0.05);②各试验组D-乳酸(D-Lac)含量、二胺氧化酶(DAO)活性均无显著差异(P>0.05);③2、3组21日龄的十二指肠胰蛋白酶活性显著升高(P<0.05),1、2组42日龄的十二指肠淀粉酶(AMS)活性显著升高(P<0.05);④1、2组21日龄的十二指肠绒毛高度(VH)显著升高(P<0.05),3组21日龄的空肠绒毛高度/隐窝深度(V/C)显著升高(P<0.05),2组21日龄的回肠VH显著升高(P<0.05),2、3组42日龄十二指肠VH、V/C显著升高(P<0.05),1、2组42日龄空肠VH显著升高(P<0.05);⑤1、2组21日龄的空肠pH显著降低(P<0.05),1、2组42日龄的十二指肠pH显著降低(P<0.05);⑥2组21日龄的盲肠乳酸杆菌、双歧杆菌数量显著升高(P<0.05),1、2组42日龄的盲肠乳酸杆菌数量显著升高(P<0.05)。综上所述,饲粮中添加PLA可以提高肉鸡十二指肠消化酶活性,降低肠道pH,促进有益菌群繁殖,且以添加1.0%PLA效果显著。

This experiment aimed to investigate the effect of polylactic acid(PLA)on the growth perfor⁃mance and intestinal function of AA broilers.192 one-day-old AA broiler chickens were randomly di⁃vided into 4 groups.The control group was fed with basic diet,and experimental groups 1,2,and 3 were supplemented with 0.5%,1.0%,and 2.0%PLA in the basic diet,respectively.The experiment lasted for 42 days.Samples were collected and measured at the ages of 21 and 42 days.The growth performance,intestinal barrier function,intestinal digestive enzyme activity,small intestine tissue structure,small in⁃testine pH value,and cecal microbiota of broiler chickens were measured.The results showed that:①compared with the control group,the average daily feed intake(ADFI)in group 1 was signifi⁃cantly increased(P<0.05)from 1 to 21 days old,and the average daily gain(ADG)in groups 1 and 2 was significantly increased(P<0.05)from 22 to 42 days old.②There were no significant differ⁃ences in D-lactic acid(D-Lac)content and di⁃amine oxidase(DAO)activity among the experi⁃mental groups(P>0.05).③The pancreatic protease activity in the duodenum in groups 2 and 3 at 21 days of age was significantly increased(P<0.05),while the amylase(AMS)in the duodenum in groups 1 and 2 at 42 days of age was significantly in⁃creased(P<0.05).④The duodenal villus height(VH)at 21 days of age in group 2 was significantly in⁃creased(P<0.05),the jejunal villus height/crypt depth(V/C)at 21 days of age in group 3 was signifi⁃cantly increased(P<0.05),the ileal VH at 21 days of age in group 2 was significantly increased(P<0.05),the duodenal VH and V/C at 42 days of age in group 2 were significantly increased(P<0.05),and the jejunal VH at 42 days of age in group 1 and group 2 was significantly increased(P<0.05).⑤The pH value of the jejunum in groups 1 and 2 at 21 days of age significantly decreased(P<0.05),while the pH value of the duodenum in groups 1 and 2 at 42 days of age significantly decreased(P<0.05).⑥The number of lactobacilli and bifidobacteria in the cecum of two groups at 21 days of age significantly in⁃creased(P<0.05),while the number of lactobacilli in the cecum of groups 1 and 2 at 42 days of age sig⁃nificantly increased(P<0.05).In summary,adding PLA to the diet can increase the activity of digestive enzymes in the duodenum of broiler chickens,reduce intestinal pH,and promote the reproduction of ben⁃eficial bacteria.The effect is significant with the addition of 1.0%PLA.