PSIV-20 Evaluation of calf performance when cows grazing native rangeland are vaccinated for bovine viral diarrhea virus and infectious bovine rhinotracheitis using either a modified live or killed vaccine
Abstract Bovine viral diarrhea virus (BVDV) is a pathogen associated with gastrointestinal, respiratory, and reproductive diseases of cattle worldwide. Vaccination of cattle with antivirals have proven effective to reduce instances of BVDV. However, vaccination protocol adoption by producers and animal response to vaccination varies. The objective of this study was to determine if administration to the dam of a modified-live viral vaccine (MLV) or killed viral vaccine (KV) would impact the growth and rumen fermentation end products of the calf. The hypothesis for this study was that calves from dams vaccinated with MLV would have improved performance. Calves (n=20) born to dams that received either MLV or KV over the course of their lifetime, were housed on rangeland at the Corona Range and Livestock Research Center in Corona, NM. Cow ruminal contents were collected at birth. Both cow and calf ruminal contents were collected at 7, 35, 63, and 205 d of age. Cow body condition score did not differ between treatments (P > 0.05) (average KV = 4.3 + 0.8 and MLV = 4.3 + 0.8) at calving. Additionally, calf birth (P =0.66) weight and weaning weight (P > 0.05) did not differ between dam vaccine type. At days postpartum x vaccine type interaction was not observed for calf ruminal pH (P = 0.20) and volatile fatty acid concentrations (P > 0.28). However, calf ruminal pH increased with age (P < 0.0001). Butyrate concentrations were least at 7 days of age (P = 0.0069). Therefore, we reject our hypothesis; calves born from dams receiving MLV do not have improved performance when compared to KV counterparts. Results indicate birth weight, weaning weight, pre-weaned calves pH, and volatile fatty acid concentration, are not impacted by dam’s vaccination type. However, impacts on calf immunity have not been evaluated and require further research.
