Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/13/2010
Publication Date: 9/15/2010
Citation: Downey, E., Conrad, E., Tait, R., Garrick, D., Ridpath, J.F., Reecy, J. 2010. Whole Genome Analysis of Response to BVDV2 Vaccinations in Angus Calves Using Bayesian Models [abstract]. One Health Symposium: People, Plants & Animals, September 15, 2010, Ames, Iowa. Available: http://vetmed.iastate.edu/onehealthsymposium. Interpretive Summary:
Technical Abstract: This study was designed to evaluate the impact of environmental factors and genetic controls on response to vaccination against bovine viral diarrhea virus type 2 (BVDV2) in Purebred American Angus beef cattle. This study utilized 245 Angus calves born in the spring (n = 139) and fall (n = 106) of 2007. Two doses of modified live vaccine (initial and booster) were administered three weeks apart. The herd was managed with two calving seasons, fall and spring. Calves, from each season, were allotted to one of two weaning/vaccination management protocols. In protocol 1, calves were weaned at initial vaccination. In protocol 2, calves were weaned at the time of booster vaccination. Viral neutralizations were conducted using cytopathic BVDV2 to determine antibody titer at initial vaccination, at booster vaccination, and 3 weeks post booster vaccination. Initial statistical analysis indicated that titer levels at initial vaccination were significantly influenced by calf age (P < 0.001), calving season (P < 0.001), and gender (P < 0.05). Weaning protocol had no significant effect (P > 0.05) on initial titer level. SNP genotypes for each animal were obtained from BovineSNP50 Infinium-beadchips. Simultaneous associations of all SNP with response to vaccination were undertaken with a GenSel Bayes-C analysis using a continuous trait model that treated SNP effects as random with an assumed fraction (pi = 0.999) having no effect on viral neutralization scores. Evaluation of posterior estimates indicates that response to vaccination is a moderately heritable (0.38) trait. Evaluation of the estimated SNP effects indicates that there are candidate genes (e.g., TLR4, PPM1B) in close proximity to the associated SNPs.