Influence of commercial inactivated and modified-live virus vaccination at time of AI on corpus luteum function and development in beef cattle

Authors: EPPERSON, KAITLIN - Texas A&M University; RICH, JERICA - Arkansas State University; MENGATTI ZOCA, SAULO - South Dakota State University; QUAIL, LACEY - Texas A&M University; ANDREWS, TAYLOR - South Dakota State University; KLINE, ADALAIDE - South Dakota State University; Carroll, Jeffery - Jeff Carroll; Sanchez, Nicole; WHITE, FRANK - Elanco Animal Health, Inc; DALY, RUSSELL - South Dakota State University; PERRY, GEORGE - Texas A&M Agrilife

Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/24/2021
Publication Date: 12/15/2021
Citation: Epperson, K.M., Rich, J.J., Mengatti Zoca, S., Quail, L.K., Andrews, T.N., Kline, A.C., Carroll, J.A., Sanchez, N.C., White, F., Daly, R.F., Perry, G.A. 2021. Influence of commercial inactivated and modified-live virus vaccination at time of AI on corpus luteum function and development in beef cattle. Society for the Study of Reproduction Annual Meeting. December 15-18, 2021, St. Louis, MO.

Interpretive Summary:

Technical Abstract: Bovine females administered a modified-live virus vaccination (MLV) shortly prior to artificial insemination experience reduced conception rates. Therefore, the objective of this study was to evaluate the impact of vaccination with either an inactivated vaccine (IV) or MLV vaccine around the time of estrus on corpus luteum (CL) development and function. Beef cows (n=86) were synchronized using the 7-day CO-Synch+CIDR protocol. On d0, animals were transrectally ultrasounded to record presence and location of dominant follicles and CL, and received either a MLV or IV based on estrus expression, follicle size, and age. Seventy animals were treated with a commercially available MLV (BoviShield Gold FP5VL5), 16 animals were treated with a commercially available IV (ViraShield 6VL5HB), and 5 animals served as unvaccinated controls. Blood samples were collected from treated animals prior to treatment on d0 and every other day through d22. Plasma was harvested and analyzed for progesterone (P4) by radioimmunoassay and interleukin-4 (IL-4), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFa), and interferon gamma (IFN-') by multiplex analysis. Between d10-13, a subset of females (n=13) were selected by treatment, dominant follicle size, and estrus expression to be ovariectomized by flank laparotomy. Control animals were slaughtered at a local abattoir on d15/16. Ovaries were obtained and CL were fixed and sectioned for histological analysis. Four random fields from each section were selected for evaluation of luteal cell populations. Concentrations of P4 and cytokines were analyzed by repeated measures using the MIXED procedure of SAS, and the GLM procedure was used to evaluate luteal cell populations, with field of view as a random effect. Females treated with MLV vaccine had reduced numbers of large luteal cells compared to IV (P<0.0001), but IV were not different from controls (P=0.11). Females treated with IV had the greatest total number of cells compared to MLV and controls (P<0.0001). Furthermore, MLV treated females had the lowest percentage of luteal cells while IV were intermediate, and control animals had the greatest percentage (P<0.0001, MLV: 1.57±0.33%, IV: 2.99±0.30%, Control: 6.45±0.33%). Based on P4 concentrations, 24% of MLV and 0% of IV had an abnormal estrous cycle following vaccination. Treatment (P=0.02), time (P<0.0001), and the interaction of treatment by time (P=0.05) influenced P4. Overall, MLV treated animals had reduced concentrations of P4 (MLV: 3.61±0.22; IV: 4.81±0.46ng/mL). When only animals that experienced a normal length luteal phase were considered, there were greater concentrations of P4 among IV females compared to MLV (MLV: 3.96±0.12; IV: 4.84±0.24ng/mL). There was no effect of treatment, time, or their interaction on concentrations of IL-4, IFN-', and TNFa (P>0.40). There was an effect of treatment by time interaction on concentration of IL-6 (P=0.03). In both treatments, among animals with normal cycles, IL-6 increased following vaccination and decreased to normal levels by d22. In the MLV treatment, among animals with abnormal cycles, IL-6 rose slower and remained elevated through d22. In summary, these data demonstrate vaccination with MLV around estrus negatively influenced luteal cell populations, P4 concentrations, and increased concentrations of IL-6.