LAUSR

The vaginal microbiota (VM) is one of the initial contacts of the neonate with microorganisms and can attribute to neonatal health outcomes. The impacts of an altered VM on post-partum dam and neonatal immune responses has not been evaluated. Betadine lavages (BL) have been used to mitigate bacterial infections within the reproductive tract by ablating the VM. Thus, this study aimed to determine if an altered VM impacts passive transfer and immune responses in post-partum dams & calves. Commercial beef cows (n = 22) were randomly assigned to either the control group (CON) or BL treatment group (BTL) two weeks before calving. Treatment BL bags were infused into the anterior vagina and cows received 1 of 3 treatments depending on calving date. Blood samples were gathered from the dam and calf at 0, 5, 30 and 60 days post-partum. Processed blood serum and dam colostrum samples were stored at -80°C. Calf serum (0 d) and dam colostrum were analyzed for immunoglobulin (IgG) concentration via a commercial ELISA. A D2Dx testing kit was used to determine immune status in both dam and calves at 1,5, 30, and 60 days by using gold nanoparticles as a pathogen substitute to identify immune system factors within serum samples. The test produces a numerical score that can be correlated to immune response strength. All IgG data were analyzed using R software. All D2Dx data were analyzed using repeated measures of ANOVA (SAS software version 9.4). There was no difference in passive transfer status between CON and BTL calves, represented by no significant differences in calf serum (P = 0.62) or dam colostrum (P = 0.32) concentrations of IgG. In dams, there was a main effect of day with immune responses decreasing at 60 days postpartum compared with 0d (P < 0.001),5d (P < 0.001), and 30d (P < 0.001). In calves, there was a main effect of day where immune responses were increased on5d compared with 30d (P = 0.046) but decreased on d 5 compared with d 60 (P = 0.005). Moreover, there was a decreased immune response in calves at d 0 (P < 0.001) and d 30 (P < 0.001) compared with d 60. In calves, there was a tendency (P = 0.08) for BTL calves to have a decreased immune response compared with CON. Interestingly, immune status fluctuated in both dams and calves from calving to 60 d post-partum. While full elucidation of causes behind these fluctuations is limited, more research evaluating their implications is warranted.