不同淀粉源饲粮对肉仔鸡小肠消化酶活性、盲肠挥发性脂肪酸含量和微生物菌群的影响

本试验旨在研究不同淀粉源饲粮对肉仔鸡小肠消化酶活性、盲肠挥发性脂肪酸含量和微生物菌群的影响。选取1日龄健康爱拔益加(AA)肉仔鸡480只,随机分为5组,每组8个重复,每个重复12只鸡。5组分别饲喂玉米淀粉、豌豆淀粉、木薯淀粉、高粱淀粉和小麦淀粉配制的半纯合等氮等能饲粮,5组饲粮总淀粉水平一致。试验期21 d。结果表明:1)与玉米淀粉组、木薯淀粉组和小麦淀粉组相比,豌豆淀粉组肉仔鸡盲肠食糜中乙酸、丙酸和总挥发性脂肪酸含量显著提高(P<0.05),高粱淀粉组盲肠食糜中总挥发性脂肪酸含量显著提高(P<0.05)。2)高粱淀粉组肉仔鸡空肠食糜淀粉酶活性显著高于其他各组(P<0.05),木薯淀粉组肉仔鸡空肠和回肠食糜脂肪酶活性以及空肠黏膜脂肪酶、淀粉酶活性显著高于其他各组(P<0.05)。3)拟杆菌门、厚壁菌门、变形菌门和柔膜菌门是肉仔鸡盲肠的优势菌门。与小麦淀粉组、豌豆淀粉组和高粱淀粉组相比,木薯淀粉组和玉米淀粉组厚壁菌门相对丰度显著提高(P<0.05)。与玉米淀粉组、高粱淀粉组和小麦淀粉组相比,豌豆淀粉组的拟杆菌门、柔膜菌门、拟杆菌属和Odoribacter相对丰度显著提高(P<0.05),变形菌门、Melainabacteria、肠杆菌科未定义属、肠球菌属和副拟杆菌属(Parabacteroides)相对丰度显著降低(P<0.05)。综上所述,淀粉来源影响肉仔鸡的小肠消化酶活性,改变盲肠的发酵模式及微生物菌群,豌豆淀粉、木薯淀粉、玉米淀粉饲粮可增加肉仔鸡盲肠中的产酸菌群,促进微生物发酵,改善肠道菌群结构,促进有益菌生长。

Effects of Different Starch Source Diets on Small Intestinal Digestive Enzyme Activities,Caecum Volatile Fatty Acid Contents and Microbial Community of Broilers

This experiment was conducted to study the effects of different starch source diets on small intestinal digestive enzyme activities,caecum volatile fatty acid contents and microbial community of broilers.A total of 480 one-day-old healthy Arbor Acres(AA)broilers were randomly divided into 5 groups with 8 replicates in each group and 12 broilers in each replicate.Broilers in 5 groups were fed semi homozygous equal nitrogen and equal energy diets prepared with corn starch,pea starch,tapioca starch,sorghum starch and wheat starch,respectively.The total starch level of 5 groups was the same.The experiment lasted for 21 days.The results showed as follows:1)compared with corn starch group,tapioca starch group and wheat starch group,the contents of acetic acid,propionic acid and total volatile fatty acid in caecum chyme of broilers of pea starch group were significantly increased(P<0.05),and the content of total volatile fatty acid in caecum chyme of broilers of sorghum starch group was significantly increased(P<0.05).2)The activity of amylase in jejunum chyme of broilers of sorghum starch group was significantly higher than that of other groups(P<0.05),and the activity of lipase in jejunum and ileum chyme and activities of amylase and lipase in jejunum mucosa of broilers of tapioca starch group were significantly higher than those of other groups(P<0.05).3)The Bacteroidetes,Firmicutes,Proteobacteria and Tenericutes were the dominant phyla in cecum of broilers.Compared with wheat starch group,pea starch group and sorghum starch group,the Firmicutes relative abundance of tapioca starch group and corn starch group was significantly increased(P<0.05).Compared with corn starch group,sorghum starch group and wheat starch group,the relative abundances of Bacteroidetes,Tenericutes,Bacteroides and Odoribacter of pea starch group were significantly increased(P<0.05),and the relative abundances of Proteobacteria,Melainabacteria unidentified Enterobacteriaceae,Enterococcus and Parabacteroides were significantly decreased(P<0.05).In conclusion,the source of starch can affect the activity of digestive enzymes in small intestine,alter the cecum fermentation patterns and microbial composition of broilers,the diets of pea starch,tapioca starch and corn starch can increase the acidogenic microbes in cecum of broilers,promote microbial fermentation,change the structure of intestinal flora,and promote the growth of beneficial bacteria.