|Tait JR., R -|
|Downey, E -|
|Mayes, M -|
|Park, C -|
|Garrick, D -|
|Reecy, J -|
Submitted to: Journal of Animal Science Supplement
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 10, 2013
Publication Date: September 17, 2013
Citation: Tait Jr., R.G., Downey, E.D., Mayes, M.S., Park, C.A., Ridpath, J.F., Garrick, D.J., Reecy, J.M. 2013. Evaluation of response to bovine viral diarrhea virus type 2 vaccination and timing of weaning on yearling ultrasound body composition, performance, and carcass quality traits in Angus calves. Journal of Animal Science Supplement. 91:5466-5476. Interpretive Summary: Calf hood vaccinations are necessary to provide protection against viral and bacterial infection particularly as animals enter feedlots later in life. However, producers question whether a strong response to vaccination reduces growth rates or meat quality at harvest because of the energy the animal invests in producing a strong immune response. In this study, calves were vaccinated at the time of weaning and followed through calf hood development, feedlot phase and harvesting. The response to vaccination was determined by measuring antibodies in serum that were generated in response to vaccination. A higher the level of antibodies reflects a more robust response to vaccination. Growth rates and meat quality factors were evaluated. It was found that there was no difference in growth rates and meat quality between animals that had a high level of antibodies following vaccination and animals that had a low level of antibodies. Thus a robust response to vaccination did not affect growth or meat quality. These findings indicate that producers should not be concerned that calf hood vaccinations have a negative effect on production.
Technical Abstract: There are concerns about antagonisms between immunity and animal productivity in livestock production. The objective of this study was to evaluate the effect of antibody levels through a response to vaccination protocol, weaning timing, and their interaction on performance and carcass quality traits in Angus beef cattle. Final antibody level and response to vaccination were based on neutralizing serum antibodies against bovine viral diarrhea virus type 2 (BVDV2). Calves were followed through development and the feedlot phase, with collection of yearling ultrasound (n=957), preharvest (n=762), and carcass (n=673) data. In this study, 48% of the animals were observed to have positively responded to the vaccine, as evidenced by higher final antibody levels compared to prevaccination antibody levels. Increased final antibody levels were significantly (P<0.05) associated with increased yearling weight and increased subcutaneous fat over the rump. An interaction between final antibody level and weaning time also was associated (P<0.05) with Warner-Bratzler shear force (WBSF) and meat pH, with a favorable, negative relationship between final antibody and WBSF in calves weaned at initial vaccination. Overall antibody response by wean time interaction had a significant (P<0.05) association with ADG and meat pH, with calves weaned at initial vaccination having a favorable, positive relationship between overall antibody response and ADG. Under both the final antibody and overall antibody response models, animals weaned at initial vaccination had significantly (P<0.05) lower intramuscular fat at yearling time and conversely higher harvest weight than animals weaned at the booster vaccination. When antibody response was grouped (none, low, high), a significant interaction (P<0.05) between antibody response group and weaning time was identified for ADG, harvest weight, and HCW. Animals weaned at the initial vaccination in the high antibody response group had the advantage for ADG, harvest weight, and HCW compared to animals in the high-response group that were weaned at booster vaccination. Linear increases in antibody response generally did not have negative effects on performance or carcass quality traits in finished cattle (P>0.05). Therefore, producers should not be concerned about decreased production or quality attributes as a result of developing a robust antibody response to vaccination for BVDV2 in beef cattle.