|Tait, Jr, R|
Submitted to: American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2010
Publication Date: 7/11/2010
Citation: Downey, E.D., Conrad, E.C., Ridpath, J.F., Tait, Jr, R.G., Reecy, J.M. 2010. Evaluating Timing of Weaning Stress on Response to BVDV2 Vaccinations in Angus Calves [abstract]. American Society of Animal Science. p. 739. 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 362 Angus calves born in the spring (n = 211) and fall (n = 151) 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. Titer levels at initial vaccination were significantly influenced by calf age (P < 0.001), calving season (P < 0.001), and gender (P < 0.05). There was no significant difference (P = 0.219) in the initial titer level between the two protocol groups. Response to initial vaccination was calculated by finding the difference between the booster titer score and the initial titer score; response to booster vaccination was the difference between the titer score 3 weeks post-booster injection and at booster injection. The overall response was calculated as the titer score 3 weeks post-booster injection minus initial titer score. Response to initial vaccination, response to booster vaccination, and overall response were significantly (P < 0.001) affected by the titer level at the beginning of the specified response period. All three response variables were significantly (P < 0.05) different across the two weaning protocol. The interaction between weaning protocol and the respective titer level was significant (P < 0.05) or suggestive (P < 0.10) of an effect on all three response variables. Based on this preliminary data, weaning protocol can affect response to vaccinations.