Effects Of Chinese Veterinary Medicine Compound On Immunity And Microbial Flora Of Piglets By Feeding Lactating Sows

The nursery period is the critical period for piglets to be slaughtered.Due to the poor resistance of piglets and difficulty in nursing,piglets are prone to diarrhea in the early stage,and they are susceptible to respiratory diseases and difficult to control in the later stage.Once there is a higher incidence,the production performance of the piglets in the entire nursery stage will be significantly reduced and the slaughter rate will be reduced.Waiting is the most troublesome problem for farms.Respiratory diseases are closely related to the lungs.Because piglets get higher immunity by sucking breast milk,the lung condition of piglets is closely related to the health status of sows during lactation.The tested drugs in this experiment consisted of Astragalus,Poria,Atractylodes and Angelica.Based on the previous findings of the research group,when the compound drug is added to the diet of lactating sows,the biological barrier,chemical barrier,mechanical barrier and immune barrier of the intestinal tract of piglets will be enhanced by sucking breast milk.According to the TCM theory of "the lungs and the large intestine are on the outside",the change of intestinal function will affect the function of the lungs.Based on the above,we take the way of maternal and child integrated health care,through adding Chinese veterinary drugs to the diet of lactating sows,to explore whether the piglets can improve the lung immunity by sucking breast milk and whether it has an impact on the lung microbial flora.The details are as follows.The test for this subject will consist of randomizing six pregnant sows,in good health and of similar body weight,into two groups of Control Group and Testment Group,three in each group.Dosing group sows were fed the Chinese veterinary medicine compound(20 g/d)in the diet from100 days of gestation for 35 days.At two time points,on the day of piglet birth(0d)and on the day of piglet weaning(21d),three piglets were slected per group per time point.Lung tissues,hilar lymph nodes as well as lower bronchial tissues were collected from piglets,and the lung microbial flora was detected using 16 S r DNA sequencing technology,The results showed that:(1)Supplementing Chinese veterinary medicine compound in the diet of lactating sows,the experimental piglets sucked breast milk to improve the cilia at the lower end of the bronchus and the morphology of lung tissue.Compared with the Control Group,the epithelial cilia at the lower end of the bronchus of the drug group are arranged more regular,grow denser and more uniform,swing in the same direction,without obvious tilt,aggregation,or fusion,and there is no obvious mucus adhesion on the mucosal surface.Meanwhile,compared with the Control Group,the Testment Group showed a clearer structure of the lung tissue,more complete alveolar structure as a whole,and less infiltration of exfoliated epithelial cells and eosinophils and lymphocytes and blood vessels in the alveolar space,without obvious inflammatory cell infiltration.(2)Supplementing Chinese veterinary medicine compound in the diet of lactating sows,the experimental piglets sucked breast milk to reduce the activity of MPO and increase the related immune factors IL-1β,IL-2,IL-6,IL-8,IL-10 and TNF-α level,raise the expression level of Ig A protein,enhance the lung CD4+T cell content,thereby improving the lung immunity of the experimental piglets.(3)Supplementing Chinese veterinary medicine compound in the diet of lactating sows,the experimental piglets sucked breast milk to change the microbial flora in the lungs of experimental piglets.Compared to the Control Group,at the phylum level,the relative abundances of Firmicutes,Desulfobacterium,and Campilobacter were significantly higher,and at the genus level,the relative abundance of Streptococcus was significantly increased,while the relative abundance of Clostridium＿sensu＿stricto＿1 and Pantoea was significantly decreased.As the piglets grow,the experimental piglets can up-regulate the relative abundance of Bacteroidota and down-regulate the relative abundance of Firmicutes by sucking breast milk to promote the development of the piglets’ lungs.To sum up,supplementing Chinese veterinary medicine compound in the diet of lactating sows,the experimental piglets improved the cilia at the lower end of the bronchus and lung tissue morphology,strengthened the lung immunity of the test piglets as well as altered lung microbial flora by sucking breast milk.It can reduce the incidence of respiratory diseases,improve the growth performance of piglets,and increase the economic benefits of pig farms.