Effect Of Different Rearing Modes And Additives On Intestinal Microflora And Intestinal Mucosal Immunity In Broilers

The experiment included two parts. The first experiment was conducted to investigate the effects of floor rearing、net rearing and outdoor hypodense rearing on growth performance, intestinal microflora and intestinal mucosal immunity of broilers.360Rose male broilers were randomly divided into3groups with6replicates per group and20broilers in each replicate. The second experiment was conducted to investigate the effects of probiotics、plant essential oil and the mixture on growth performance, intestinal microflora and intestinal mucosal immunity of broilers in the base of net rearing.480Rose male broilers were randomly divided into4groups with6replicates per group and20broilers in each replicate. The4groups broilers were fed with a basal diet, a basal diet added with0.3%o bacillus licheniformis, a basal diet added with0.25‰plant essential oil and a basal diet added with the mixture of0.3‰bacillus licheniformis and0.25‰plant essential oil respectively. The experiment lasted for42days. The results showed as follows:1、The effects of floor rearing、net rearing and outdoor hypodense rearing on growth performance, intestinal microflora and intestinal mucosal immunity of broilers.The floor rearing group and the net rearing group were significantly better than the outdoor hypodense rearing group on growth performance (P<0.05), and there was no significant difference on performance between the floor rearing group and the net rearing group (P>0.05). But compared with the net rearing group, the floor rearing group and outdoor hypodense rearing group were significantly decreased the ratio of feed to gain (P<0.05). Compared with the floor rearing group and the net rearing group, the outdoor hypodense rearing group were significantly increased mortality (P<0.05).The microbial similarity in duodenal was high, while the microbial similarities in jejunum, ileum and caecum were low, and the microbial similarity decreased from proximal gut to distal gut gradually. Among the different groups, the microbial variety of the floor rearing group were better than the outdoor hypodense rearing group and the net rearing group in duodenal jejunum and ileum. There were no significant differences on contents of lactobacillus and bifidbacteria among the three kinds of rearing modes (P>0.05).The relative expression of IL-6and INF-y in jejunum mucosal of the outdoor hypodense rearing group were both significantly higher than the floor rearing group and the net rearing group (P<0.05). The contents of sIgA in the jejunum of the net rearing group were significantly higher than the floor rearing group and the outdoor hypodense rearing group (P<0.05). The results showed that, compared with the other two rearing modes, broilers had a higher level of intestinal mucosal immunity in net rearing group.2、The effects of probiotics、plant essential oil and the mixture on broilers growth performance, intestinal microflora and intestinal mucosal immunity.Compared with the contral group, body weight in the probiotics group and the mixture group were significantly increased (P<0.05), but had no significant influence on feed to gain (P>0.05). There was no significant difference on growth performance between the plant essential oil group and the control group (P>0.05).Probiotics and plant essential oil had a greater influence on the microbial similarity in early rearing period than that of late rearing period, and had a greater influence on that of ileum and jejunum than duodenal and caecum. In the whole rearing period the microbial variety in duodenal、jejunum and ileum of all experimental groups were better than that of the control group. Compared with the control group, the contents of lactobacillus in duodenal、jejunum and caecum increased in all experimental groups. In the late rearing period, the contents of bifidobacteria in duodenal、jejunum and ileum increased in all experimental groups.Compared with all experimental groups, the relative expression of IL-6and INF-y in the jejunum mucosal significantly increased in the control group (P<0.05). The contents of sIgA in the jejunum was significantly increased in all experimental groups (P<0.05).The results showed that, probiotics and plant essential oil could significantly improve the level of intestinal mucosal immunity of broilers.