Effects Of Bacillus Subtilis On Growth Performance And Blood Biochemical Parameters And Intestinal Health Of Weaned Bamboo Rats

Bamboo rat is a special breeding animal with high economic value,but weaning bamboo rat has frequent intestinal diseases,low survival rate and slow growth.As a green feed additive,Bacillus subtilis has antioxidant functions,enhances immunity,improves intestinal health and other physiological functions,and is currently widely used in livestock and poultry production.In this experiment,a 40-day-old weaned Yinxing bamboo rat was selected as the research object to explore the effects of Bacillus subtilis on the production performance,blood biochemical indicators,immune and antioxidant functions,and intestinal health of weaned bamboo rats.96 weaned bamboo rats of similar weight and good health were randomly divided into 4 groups with 6 replicates in each group and 4 bamboo rats（male and female half）in each repeat.A control group and three test groups are set up in the four groups,and the three test groups are respectively referred to as a test groupⅠ,a test groupⅡ,and a test groupⅢ,the control group was fed with basic diet,and three experimental groups were supplemented with 2.22×10¹²cfu/kg,4.44×10¹²cfu/kg,and6.66×10¹²cfu/kg of basal grass Bacillus.The test period is 60d,and the first 30d is the pre-test period.At the end of the test,the control group and the higher test group III of the three test groups are selected for slaughter sampling.Each group selects 6 bamboo rats.Next,one bamboo rat was randomly selected for each repetition.The results show that:（1）growth performance:In the early stage of the test,compared with the control group,the BW、ADG and survival rates of the test groupsⅠandⅡandⅢwere improved to varying degrees on the 30th day,but the differences were not significant（P>0.05）;ADFI of concentrates in test groupⅠandⅡandⅢshowed a significant increase（0.05<P<0.1）;compared with the control group,the ADG in the test group III was significantly increased（P<0.05）;there was no significant change in the ADFI and the F/G of the coarse material and the fine material between the groups（P>0.05）.During the whole period of the test,compared with the control group,the ADFI of the concentrates in the testⅠandⅡandⅢgroups was significantly increased（P<0.01）;there was no significant difference in crude ADFI and total ADFI between the groups（P>0.05）;Compared with the control group and the test groupⅠ,the FBW and ADG in the test group III were significantly increased（P<0.05）,and the coarse F/G and total F/G were significantly decreased（P<0.05）.（2）Gastrointestinal contents and stool pH:Compared with the control group,the stool pH of the test groupⅡand groupⅢwas significantly reduced（P<0.05）;the pH of the contents of the cecum of the test group III was significantly reduced（P<0.05）,and the pH of the contents of the jejunum had a significant trend（0.05<P<0.1）;Compared with the control group,the contents of gastric,duodenum and ileum contents in test groupⅢwere not significantly different（P>0.05）.（3）Serum metabolites:The addition of 6.66×10¹²cfu/kg Bacillus subtilis had no significant effect on the levels of ALT,ALP,GLU,UREA,HDL,TP,and P in serum of weaned bamboo rats（P>0.05）;Compared with the control group,the serum CREA,LDL,and TC contents in the test III group showed a significant decrease（0.05<P<0.1）,and the contents of AST,UA,TG,and Ca decreased by 39.85%,69.86%,34.85%,19.42%,The difference was significant（P<0.05）.（4）Immunity:The addition of 6.66×10¹²cfu/kg Bacillus subtilis had no significant effect on the contents of LZM,IgG,C4,and TP in the serum of weaned bamboo rats（P>0.05）;Compared with the control group,the serum IgA and IgM contents and the SIgA contents in the jejunum and ileum intestinal mucosa of the test III group were significantly increased（P<0.01）;the C3 content in serum and SIgA content in duodenal intestinal mucosa were significantly increased;Compared with the control group,the spleen index and thymus index of the experimental group III increased by 27.27%and 25.00%,respectively,and the differences were significant（P<0.05）.（5）Antioxidant capacity:Compared with the control group,the activities of T-AOC,GSH-Px,SOD,and CAT in the serum of the experimental group III were increased by94.28%,53.68%,103.62%,and 40.91%,respectively,all of which were significantly different（P<0.01）,and the MDA content Reduced by 47.37%,the difference is significant（P<0.05）;Compared with the control group,the T-AOC,SOD,and CAT activities in the liver of the experimental group III were increased by 26.44%,25.40%,and 21.72%,respectively,and the MDA content was reduced by 32.81%,all of which were significantly different（P<0.01）,but has no significant effect on GSH-Px activity（P>0.05）.（6）Intestinal morphology:Compared with the control group,the duodenal VH in the test group III showed a significant increase（0.05<P<0.1）,and the VH/CD significantly increased（P<0.01）;the jejunum VH and VH/CD increased by 33.18%and 50.39%,respectively,and the differences were extremely significant（P<0.01）;the ileum VH/CD showed a significant increase（0.05<P<0.1）,and VH was not significant Impact（P>0.05）;There was no significant change in CD in each intestine of the control group and the experimental group（P>0.05）.（7）Intestinal flora:Compared with the control group,the Chao index and Observed＿species index in Alpha Diversity analysis increased by 9.63%and 12.61%,respectively,both of which were significantly different（P<0.05）,but the flora at the level of phylum and genera There was no significant difference in composition（P>0.05）.Conclusion:Adding Bacillus subtilis to the diet can effectively improve the survival rate,production performance,enhance the body’s antioxidant and immune functions,and improve intestinal health.The performance of weaning bamboo rats fed with6.66×10¹²cfu/kg Bacillus subtilis in diet was the best.