乳果糖替代饲用抗生素对黄羽肉鸡免疫器官指数及小肠黏膜免疫的影响

Effects of Lactulose Substitution for Antibiotics Feed Additive on Immune Organ Index and Intestinal Mucosal Immune of Yellow Chicken

为研究基础日粮中添加乳果糖替代饲用抗生素对黄羽肉鸡免疫器官指数及小肠黏膜免疫的影响,将180只1日龄体重相近、健康的黄羽肉鸡随机分为5个处理组,每个处理组3个重复,每个重复12只。阳性对照组在基础日粮中添加0.30g/kg的那西肽和0.25g/kg的硫酸粘杆菌素;阴性对照组饲喂基础日粮;试验Ⅰ、Ⅱ、Ⅲ组在基础日粮中分别添加5,10,15g/kg的乳果糖。分别在饲喂到45日龄及77日龄时,取试验鸡称重,翅静脉采血,颈部放血屠宰,摘取胸腺、脾脏、法氏囊进行称重,用于计算免疫器官指数,剥离十二指肠、空肠、回肠用于测定小肠黏膜蛋白质中溶菌酶含量、十二指肠黏膜蛋白质中SIgA(分泌型免疫球蛋白A)的含量、肠道内容物中细菌数量及回肠内容物中有机酸浓度。结果表明,与阴性对照组相比,每千克基础日粮中添加5g乳果糖替代黄羽肉鸡饲用抗生素后提高了肠道内容物中细菌数量及回肠内容物总酸的浓度,提高了肠黏膜蛋白质中溶菌酶的含量、十二指肠黏膜蛋白质中SIgA含量,并且这种作用在45日龄时强于75日龄时,但对免疫器官指数无显著影响。

An experiment was conducted to study the effects of substituting lactulose for forage antibiot- ics in diet on immune organ index and intestinal mucosal immune of the yellow chicken. One hundred eighty one-day-old yellow chicken were randomly divided into two control groups and three trial groups with 3 replicates per group and 12 chickens per replicate. The positive control group was fed with diet sup- plemented by 0.30% Nosiheptide and 0.25% sulfate colistin premix. Negative control group was fed with basal diet. Birds in the trial group Ⅰ , Ⅱ and Ⅲ were fed with diet supplemented by 5,10,15 g/kg lactu- lose, respectively. At 45 d and 77 d, birds were killed for thymus, spleen, bursa, duodenum,jejunum,ileum, and blood sample collections and weights. The immune organs index,intestinal mucosal SIgA content and lysozyme content of protein,the amount of bacteria in intestinal contents and organic acid concentration in ileum were measured. The results showed that the amount of bacteria in intestinal contents, total acid con- centrations in ileum contents, SIgA and lysozyme contents in mucosa protein were increased in yellow chicken fed with diet supplemented by 5 g/kg lactulose compared with negative control group,and those effects were more significant at 45thd than at 75thd. Immune organ index were not significantly inhibited.