Research And Correlation Analysis Of Reproductive Hormone And Genital Tract Flora In Simmental Cattle With Repeated Infertility

Repeated infertility is one of the main problems that have plagued the breeding industry for a long time,and the same is true for Simmental cattle breeding.Studies have shown that hormone changes were inseparably related to reproductive activities.The predecessors had problems with the reproductive tract flora of various breeds of cattle.But little research on the reproductive tract flora of Simmental cattle.Therefore,this test used ELISA to detect E2,PROG,FSH,LH,PGE2,Gn RH and LEP of healthy and repeatedly infertile Simmental cattle in four periods,and used cotton swabs to take secretion from the middle vaginal by 16 S r DNA.Analyze the vaginal flora,compare the differences of reproductive hormones,leptin and reproductive tract flora between healthy and repeatedly infertile Simmental cattle,and explore their correlations between reproductive hormones and reproductive tract bacteria.The main test results are as follows:1.The E2 concentration of the healthy group during the postpartum recovery period and the first estrus period were significantly higher than that of the repeated infertility group(P < 0.05),and the FSH concentration of the healthy group during the first and second estrus period were significantly higher than that of the repeated infertility group(P < 0.05),the Gn RH concentration of the second estrus of the healthy group was significantly higher than that of the repeated infertility group(P < 0.05),the PROG and PGE2 concentrations of the third estrus healthy group were significantly higher than those of the repeated infertility group(P < 0.05).The correlations in the reproductive hormones between the healthy group and the infertile group are different.2.Firmicutes,Bacteroides,and Proteobacteria are the dominant bacteria in the phylum levels of the healthy group and the repeated infertility group,among which Firmicutes are the most abundant;in the genus level,Ruminococcaceae＿UCG-005,Ruminococcaceae＿UCG-010,Histophilus are the dominant bacteria.Among them,the most abundant genus in the healthy group is Ruminococcaceae＿UCG-005,and the most abundant genus in the repeated infertility group is Ruminococcaceae＿UCG-010.3.At the phylum level,the reproductive hormones and leptin of the healthy group were mainly negatively correlated with Verrucomicrobia(P < 0.05),futhermore the reproductive hormones and leptin of the repeated infertility group were mainly positively correlated with Kiritimatiellaeota(P < 0.05);in the genus level,the hormones of the healthy group were significantly correlated with the genus of bacteria(P <0.05),while the multiple infertility group only had a significant correlation between LH and the genus(P <0.05).The above research results show that the changing laws of reproductive hormones are different in different periods,in addition the hormones are related and affect each other.The insufficient concentration of E2,PROG,PGE2,and Gn RH may be related to the repeated infertility of Simmental cattle.The concentration of reproductive hormones should be tested during production,and if it is lower than the healthy range,it should be refilled in time.Reproductive hormones mainly affect the changes of Verrucomicrobia and Kiritimateellaeota.LH affects the abundance of Spirochaetes.Spirochaetes,Lentisphaerae,Verrucomicrobia,Kiritimatiellaeota,Rikenellaceae and Bacteroides may be related to the repeated infertility of Simmental cattle.