Studies On Effect Of Probiotics On Chicken Immunity Levels And The Evaluation Of Immune Protective Effect On Eimeria Tenella

Chicken coccidiosis is distributed globally, it’s ubiquitous and great harm to the poultry industry. It hinders the development of the poultry industry and cause huge economic losses. Probiotics is expected to be a new way to prevent and control coccidiosis. The range of probiotics is wide so we chose lactobacillus as example to explore the effect of probiotics on chicken immunity levels and the evaluation of immune protective effect on E.tenella. In this study, we chose up to 31-day-old male broiler chickens for experimental animals and three strains of probiotics. Three lactobacillus strains were Lactobacillus rhamnosus ATCC53103、Pediococcus acidilactici ATCC8042、Lactobacillus plantarum WCFS1. Two hundred and fifty 1-day-old healthy male broiler chickens were randomly assigned to A、B、C、D、E five groups, each group had fifty chickens. They were feed in the enviroment where no coccidiosis and strict sterilization. During 1 to 21-day-old chickens in group A and B were drenched normal saline 200μL each, chickens in group C, D and E were drenched corresponding strains 2×108cfu/200μL each on an empty stomach. Chickens in group C were drenched Lactobacillus rhamnosus ATCC53103, in group D were drenched Pediococcus acidilactici ATCC8042, in group E were drenched Lactobacillus plantarum WCFS1. When chickens were 22-day-old, each group was executed twenty-five chickens to detect the proliferative capacity of lymph cell in peripheral blood, the percentage of CD3+CD4+ and CD3+CD8+T lymph cells in peripheral blood, the content of IFN-γ、IL-2 in serum, the content of Ig G in serum and the content of SIg A in duodenal chyme. Besides group A, the rest of other groups chickens were inoculated with 5×104 E. tenella sporulated oocysts. Eight days later, when chickens were 31-day-old executed all the chickens to detect above-mentioned immune indices and the relative weight gain rate, the score of blood fece, the scores of cecal lesion, the value of ocysts in cecum, the output rate of ocysts, the anticoccidial index and the histopathologic slide of each group chickens. The results were as fllows:(1) The effect of lactobacillus on E. tenella infect chickens immunity levels: before and after infected with E. tenella chickens were 22-day-old and 31-day-old detected the immune indices, the result showed that, before and after infected with E. tenella all the three strains of lactobacillus could enhance the proliferative capacity of lymph cell in peripheral blood, promotethe generation of CD3+CD4+ and CD3+CD8+T lymph cells, and then raise the content of IFN-γ and IL-2 in serum, thereby the cellular immunity levels were enchanced; more over they can also raise the content of Ig G in serum and the content of SIg A in duodenal chyme and then enhance the humoral immunity levels. Among the three lactobacillus strains Lactobacillus rhamnosus ATCC53103 had the best immunoprotective, Lactobacillus plantarum WCFS1 come second, Lactobacillus plantarum WCFS1 was the worst.(2) Evaluate the immune protective effect of lactobacillus on E. tenella: the result showed that before and after infected with E. tenella the mean weight gain of three lactobacillus groups were higher than the group B, and the group C were significantly differences with the group B(P﹤0.05); the result of the scores of blood fece showd that three lactobacillus groups were lower than the group B, and the group C was the lowest; the result of the scores of cecal lesion showed that the scores of group B was 3.25, it was the highest group among four groups, it was highly significant with the group C(P﹤0.01) and significantly differences with the group D(P﹤0.05); the result of the output rate of ocysts showed that three lactobacillus groups were lower than the group B, and the group C was the lowest; the anticoccidial index of three lactobacillus groups were 152.40, 123.22 and 133.26, they all in the range of 120~160, so the three lactobacillus strains had medium effects on resisting coccidiosis. Among the three lactobacillus strains Lactobacillus rhamnosus ATCC53103 had the best effects on resisting coccidiosis, Lactobacillus plantarum WCFS1 come second, Lactobacillus plantarum WCFS1 was the worst.