Effects Of Different Fiber Source Diets On Growth Performance And Immune Performance Of Growing Rabbits

The purpose of this study was to investigate the effects of different fiber-derived diets on the proliferation and apoptosis of M cells in the appendix tissue of growing rabbits,including the production performance,intestinal development,intestinal and blood immune indexes,and the effects of different fiber-derived diets on the growth of rabbits.It provides a theoretical basis for other animals and humans on the mechanism of nutritional factors regulating intestinal mucosal immunity,and provides support for the research on nutritional factors as antigen immunomodulators.One hundred and twenty New Zealand rabbits,half male and half female,weaned for three days were selected and divided into three groups according to the dietary fiber sources,namely peanut seedling group,corn straw group and leymus chinensis group,The test period was 45 d.(1)There were extremely significant differences in ADF,ADG and F/G among the three groups(P<0.01,P<0.01,P=0.03).The peanut seedling test group was better than the corn straw group and lepidium chinensis group,and the highest indexes of ADF,ADG and F/G all appeared in the peanut seedling group.(2)At the end of the experiment,samples of duodenum and ileum were collected for paraffin embedding for HE staining,and the villus length and cryptic depth were observed under the microscope.The longest duodenal and ileal villi of the peanut seedling test group were significantly different from those of the corn stalk group and the leymus chinensis group(P<0.01),but the leymus chinensis group was better than that of the peanut seedling group in terms of crypto depth(P<0.05).However,the comprehensive evaluation index of intestinal development was V/C(villi length/crypto depth).Finally,the intestinal development of the leymus chinensis group was better than that of the peanut seedling group and the corn straw group.(3)After the rabbits were fed with different fiber diets for 45 d,BrdU reagent was intravenously injected into the ear margin,and lumbrical tissues were collected at 2h,24 h and72h,respectively.The proliferation and apoptosis of M cells were observed by immunohistochemistry.The results showed that the proliferation of M cells in the three groups was significantly different at 2h,24 h,and72h(P<0.01,P<0.01,P<0.01),indicating that different fiber-derived diets had an effect on intestinal M cells.Moreover,compared with corn straw and leymus chinensis fiber-derived diets,peanut seedlings could promote the proliferation of M cells.The apoptosis of M cells was determined by TUNEL kit at 2h,24 h and 72 h,and the number of apoptotic cells in the leymus chinensis group was significantly higher than that in the corn straw group and peanut seedling group(P<0.01,P<0.01,P<0.01).This comprehensive test research,peanut seedling as a single fibre source diet feeding experimental rabbit compared with corn stalk and fiber source feed in feeding rabbit growth rate,feed conversion ratio,and the status of the intestinal immune cells have a significant advantage,diarrhea rate and the mortality rate is relatively low,affect the diet with different fiber source feeding rabbit intestinal vermiform appendix M cell proliferation and apoptosis.There was a significant increase in the proliferation of M cells in the lumbrical.The higher number of M cells proliferation indicated that the body could start mucosal immunity more quickly,which would improve intestinal health and disease prevention.