|Tait Jr, R|
Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/16/2009
Publication Date: 3/16/2009
Publication URL: http://adsa.asas.org/midwest/2009/abstracts/09MWAbstracts.pdf
Citation: Schneider, M.J., Tait Jr, R.G., Ridpath, J.F., Reecy, J.M. 2009. Environmental Factors Impacting Response to Bovine Viral Diarrhea Vaccines in Angus Calves [abstract]. American Society of Animal Science, Midwestern Section. p. 1. Available: http://adsa.asas.org/midwest/2009/abstracts/09MWAbstracts.pdf. Interpretive Summary:
Technical Abstract: The objective of this study was to evaluate the impact of environmental factors on the serological response to commercial bovine viral diarrhea type 2 (BVDV2) vaccinations in Angus cattle for inclusion as fixed effects into subsequent genetic evaluations for response to vaccination. This study utilized 353 Angus calves born in spring (n = 176) and fall (n = 177) calving seasons of 2006 in the Iowa State University Angus Breeding Project. Two vaccinations, initial and booster, were administered 3 weeks apart. Spring calves were weaned and given initial vaccination at the same time, while fall calves were weaned at the time of booster vaccination administration. Serum neutralization tests were conducted using cytopathic BVDV2 to measure titer level in all cattle. Titer levels at the time of first vaccination were not influenced by gender of calf (P = 0.13) but were influenced by calving group (P < 0.001) and calf age (P < 0.001). This observation may result from the decline of maternal antibodies transferred through colostrum with age. There was no interaction between group and age of calf covariate (P = 0.89) for titer level at the time of first vaccination, indicating maternal antibodies have a similar half-life in both groups. However there was a significant difference (P < 0.001) among groups for titer level following initial vaccination, with the group experiencing the stress of weaning at time of initial vaccination developing a lower titer level. Additionally, titer level at time of initial vaccination was a significant (P < 0.001) effect for predicting response to initial vaccination with animals having a higher initial titer level experiencing a smaller increase in titer change. Based on this initial study, we have adjusted experimental protocols for subsequent work to collect samples to evaluate individual animal rate of maternal antibody decline and to remove confounding of stress of weaning with calving season effects.