31 Correlation of the Reproductive Microbiome and Cytokine Profiles with Plasma Progesterone Concentrations in Postpartum Beef Cows Prior to Timed Artificial Insemination

Abstract Female sex steroid hormones have been shown to interact with cytokines within the immune system help influence fertility. Previous research has indicated that shifts in commensal bacteria are associated compromised reproductive performance during postpartum period, yet evaluation of how female hormone progesterone (P4) influences these microbial is not fully understood. The objectives this study were determine 1) relationship between P4 concentrations and cytokine concentrations, 2) microbiome. Twenty Bos indicus-influenced beef cows (~60 days free health issues) weighed, body condition scored then subjected indicus prostaglandin 5 day (d) + CIDR protocol beginning on d -8 timed artificially inseminated 0. Blood samples collected d-3, -1, 0, 28. Cytokines microbiome evaluated using vaginal uterine flushes -3 d-1. Experimental groups assigned by 28 pregnancy status, determined transrectal ultrasonography, resulting Open (n = 13) Pregnant 7) females. Bacterial community analyses conducted targeting V4 hypervariable region 16S rRNA gene. Plasma -1 quantified per manufacturers’ instructions a double-antibody RIA kit. Cytokine plasma RayBiotech Quantibody Bovine Array Q1 kit manufacturer’s instructions. Statistical GLM procedure CORR SAS. did differ status (P > 0.05) but decrease from (0.89 vs. 0.08 ± 0.23 ng/mL, respectively; P 0.02). There no significant correlations 0.05). Interferon-alpha (IFNα) positively correlated (r 0.41; 0.01). Concentrations interleukin (IL)-1F5 negatively -0.32; 0.04). relative abundance genus Methanobrevibacter was both experimental 0.35; Within flushes, there tendency for negative correlation Bacteroides -0.31; Alternatively, positive concentration Streptococcus 0.47; 0.01) 0.37; 0.02) flushes. These results suggest may be relationships several circulating concentrations; therefore, potentially suggesting immunomodulatory activities P4. Overall, alludes having vital role responses. Further investigation local effects tract responses bacterial could provide greater insight into mechanisms improve fertility cattle.