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

An experiment was conducted to study the effects of substituting lactulose for forage antibiotics 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 supplemented 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 lactulose,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 concentrations 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.