Effects Of Astragalus Membranaceus Compound On Growth,Immune And Intestinal Microbes Of Holstein Calves

No.194 announcement of the Ministry of Agriculture and Rural Affairs declared that the use of antibiotics in the feed industry will be completely banned in 2020.Chinese herbal medicine has the function of antibacterial sterilization,which could improve the ability of anti-inlammatory in animals.It’s a kind of natural green feed additive with development prospect.Astragalus membranaceus has the function of immunoregulation,antibacterial,antiphlogistic,anti-stress and growth-promoting.At present,the useage of Astragalus membranaceus in pigs,poultry and ruminants has achieved some effects.But there are few studies on the useage of astragalus membranaceus compound with other herbs in calves.In this experiment,astragalus membranaceus compound was selected to fed newborn Holstein calves to study the effects of astragalus compound on the growth performance,immune index and intestinal microbes on calves,which could provide theoretical support for the application of astragalus compound in calves.Single factor experiment was selected and 36 newborn Holstein calves were randomly divided into three groups:control group C(n=12),experimental group H(n=12)and experimental group E(n=12).Each calf is one replicaion.The milk was fed normally in the control group,and 2 ml/kg and 4 ml/kg astragalus compound concentrate were added to the milk in the experimental group H and E respectively.The pre-feeding period was 15 days and the experimental period was 30 days.The results showed that:(1)The final body weight was 69.92±2.87 kg in group C,75.92±1.41kg in group H and 76.32±3.32kg in group E.The final weight of group H and E was significantly higher than that of control group(P<0.01),but there was no significant difference between the two experimental groups(P>0.05).(2)Compared with the control group C,at 30 day old,the content of serum IgG was increased by 49.74%in group E(P<0.01)and 24.36%in group H(P<0.05),the content of IgA and IgM in group E were higher than that in group H and group C(P<0.01).At 45 day old,the content of serum IgA increased by 54.58%in group E(P<0.01),22.17%in group H(P>0.05),the content of serum IgM in group E and H increased by 22.83%(P<0.05)and 15.20%(P>0.05),and the content of serum IgG in group H and E increased by 50%(P<0.01)and 32.74%(P<0.01),respectively.(3)Astragalus compound could increase the diversity of intestinal microbes and the relative abundance of beneficial bacteria in calves.With the increase of age,the microbial βdiversity decreased and α diversity increased in all groups,and the relative abundance of Ruminococcus2,Treponema and Osillibacter increased.At 45 days old,the relative abundance of Phascolarctobacterium and Treponema increased,while the relative abundance of Ruminococcus2 and Osillibacter decreased compared with the control group C.In summary,adding astragalus compound in milk could improve the growth performance,immune index and intestinal microbes in calves,and add 4 ml/kg astragalus compound is more suitable.