45 Vaccine Protocol Influences Immune Phenotype of Weaned Beef Calves

Abstract Vaccination is one mechanism used as a preventative measure to decrease morbidity and mortality due bovine respiratory disease (BRD), but vaccination efficacy inconsistent. Therefore, the objective of this study was compare effect inactivated (INA) vs. modified live (MLV) viral vaccines on immune phenotype weaned beef calves. Mixed-sexed pens with equal numbers heifers steers were randomly assigned receive either INA (Vira Shield 6) or MLV (Titanium 5) treatments at d 0 (initial) booster (28 d). A subpopulation (n = 28) 18) identified from these treatment balanced for treatment. Samples obtained prior 14 28 post-initial again post-booster. All animals weighed collection days. Data analyzed using GLM MIXED procedures SAS repeated measures. × day interaction occurred cortisol vaccination; calves had greater (P 0.05) than At post-booster, < total IgG isotypes IgG1 IgG2. cytokine concentrations associated humoral cell-mediated responses. Conversely, serum neutralizing antibodies antigens vaccine significantly in 0.05). Calves receiving heavier end study. These data imply that protocol resulted differential phenotypes. More specifically, indicated stimulation both response. In contrast, indicative bias towards Further research should be done determine protective value