Effects Of Calf Supplementation On Intestinal Microbial Diversity,Growth Performance And Blood Index

The purpose of this experiment was to study the effects of supplementary feeding on the calves' body condition,blood growth and metabolism indexes,and intestinal flora.Through the analysis of pure grazing and "grazing+supplementary feeding" methods,the calf body size and weight changes,blood growth and metabolism indexes and intestinal flora structure changes are analyzed to provide a theoretical basis for improving calf production performance and health.Select 16 grazing Simmental calves with close and healthy condition,male and female half.Randomly divided into grazing group(DF group)and supplementary feeding group(DB group).The grazing group follows the grazing pastures of the mother animal,and the supplementary feeding group performs supplementary feeding on the basis of grazing.Experiment 1:In order to study the changes of microbial community in calf intestines by supplementary feeding,collect rectal fecal samples of calves in grazing group and supplementary feeding group,and detect and identify the microbial community in intestine by 16S sequencing technology to determine intestinal bacteria.Group changes.The results suggest that the calf flora alpha diversity and abundance in the supplementary feeding group is higher than that of the grazing group,and the difference is not significant(P?0.05);Significantly increased at the beginning of the experiment(P ?0.05),although the grazing group improved but not significantly(P?0.05);the wart micromycota in the supplementary feeding group was significantly higher than the grazing group at the gate level(P ?0.05),and the Proteobacteria was significantly lower than the grazing group(P ?0.05).At the family level,the relative abundance of the rumeniaceae group in the feeding group was significantly higher than that in the grazing group(P?0.05),Akkermansiaceae was significantly higher than that in the grazing group(P?0.05),and Enterobacteriaceae was significantly lower than that in the grazing group(P?0.05).The results of Spearman correlation score showed that blood glucose concentration was significantly negatively correlated with Rumenaceae,and the related indexes of fat anabolic metabolism were negatively correlated with Rumenaceae.Among them,TG showed that it was also negatively correlated with Bacteroideae and Rikeniaceae.On the contrary,fat catabolism-related indicators are positively correlated with Rumen Bacteria;most growth hormones are positively correlated with Bacteroideae and Riken Bacteriaceae.Experiment 2:Study the changes of body weight of two groups of calves in different periods.The results suggest that the daily weight gain and body height increase of the supplementary feeding group are higher than that of the grazing group,but the difference is not significant(P?0.05).Experiment 3:Collect blood samples of jugular veins of calves in grazing group and supplementary feeding group,and determine biochemical indexes(GLU,TG,TC,HDL-C,LDL-C),hormone indexes(GH,IGF-I,THS,T3,T4,LEP,APN,GC,INS),enzyme activity indicators(HSL,FAS,LPL,ACC),immune indicators(IgG,IL-1,IL-2,TNF?).The results showed that the TC content in the grazing group was significantly higher than that in the supplementary feeding group(P?0.05),and the increase in HDL-C in the supplementary feeding group was significantly higher than that in the grazing group(P ?0.05).The levels of GH,IGF-I,THS,T4 and GC The supplementary feeding group was significantly higher than the grazing group(P?0.05),and there were no significant differences in other indicators(P?0.05).