Effects Of Different Body Conditions On Intestinal Flora And Short-chain Fatty Acids And Blood Lipid Metabolism In Pregnant Cattle

The aim of this study was to investigate the effects of different body conditions on blood lipid metabolism,intestinal flora and short-chain fatty acids(SCFAs)in pregnant cattle.Through the analysis of blood lipid metabolism index,maternal body weight and forage nutrient composition,intestinal flora structure and short-chain fatty acid analysis,it provides a theoretical basis for improving the reproductive performance and production performance of pregnant cattle.The study was divided into obesity group and standard group according to the body condition score test,each group of 6 cows.The test contents are as follows:Experiment 1:Study the changes of body weight,body weight and nutrient composition of pasture cows in obese and standard body conditions.The results suggest that during the test period,the weight,chest circumference and abdominal circumference of the obese group were significantly higher than the standard group(P<0.05).The weight,height,cross height,body length,and width of the pregnant cow were The chest circumference and abdominal circumference increased as the trial period increased.Experiment 2:Collecting jugular vein blood samples from obese and standard groups,and measuring biochemical indicators related to lipid metabolism in serum(TG,TC,HDL-C,LDL-C),enzyme related indicators(FAS,ACC,LPL,HSL)And related hormones(LEP,ADPN,GH,GC,INS),to explore the changes of blood lipid metabolism indicators in pregnant cows with different body conditions.The results showed that the levels of triglyceride(TG),leptin(LEP),fatty acid synthase(FAS)and acetyl-CoA carboxylase(ACC)in the obese group were significantly higher than those in the standard group(P<0.05),serum high-density lipoprotein cholesterol(HDL-C),growth hormone(GH),adiponectin(ADPN)and hormone-sensitive lipase(HSL)were significantly lower than the standard group(P<0.05),The content of lipoprotein lipase(LPL)was significantly lower than that of the standard group(P<0.01).Experiment 3:The content of SCFAs in the intestines of two groups of cows was determined by GC-MS,and the trends of SCFAs in the feces of pregnant cows in different body conditions were investigated.The results suggested that the contents of acetic acid,propionic acid,butyric acid and total SCFAs in the feces of pregnant cows in the obesity group were significantly lower than those in the standard group at the early and middle stages of the experiment(P<0.05),and there was no significant difference in the content of SCFAs between the two groups at the later stage of the experiment(P>0.05).During the test period,the contents of acetic acid,propionic acid,butyric acid and total SCFAs all showed a trend of increasing first and then decreasing,reaching a peak in the middle of the test.Experiment 4:In order to study the changes of microflora in the intestinal tract of pregnant cows with different body conditions,fecal samples from the above obese group and normal group were taken,and the microflora in the intestinal tract was detected and identified by 16S sequencing technology,so as to determine the changes of intestinal microflora.The results showed that at the phylum level,the intestinal Firmicutes of pregnant cows in the obesity group increased,Bacteroidetes and Verrucmicrobia decreased,but the differences were not significant(.P>0.05).At the family level,the contents of Ruminococcaceae and Peptostreptococcaceae increased in the obese group,while the contents of Rikenellaceae,Prevotellaceae and Akkermansiaceae decreased,but the differences were not significant(P>0.05).Spearman correlation analysis results showed that Spirochaetes,Fibrobacteresy Spirochaetaceae and Fibrinobacteriaceae had significant positive correlation with propionic acid(P<0.05)and extremely significant positive correlation with butyric acid(P<0.01).Muribaculaceae was significantly positively correlated with acetic acid,propionic acid,butyric acid and total SCFAs(P<0.05).Bacillaceae was significantly negatively correlated with acetic acid(P<0.05).Peptococcaceae has significant negative correlation with total SCFAs(P<0.05),and extremely significant negative correlation with acetic acid(P<0.01).Paludibacteraceae has a significant negative correlation with butyric acid(P<0.05),and Enterobacteriaceae has a very significant negative correlation with acetic acid,propionic acid and total SCFAs(P<0.01).