Health performance of feeder calves sold at conventional auctions versus special auctions of vaccinated or conditioned calves in Ontario.
OBJECTIVE
To compare health performance during the first 28 days in the feedlot for vaccinated or conditioned feeder calves sold through special auctions in Ontario with health performance for calves sold through conventional auctions in the province.


METHODS
Cohort study.


METHODS
12,313 calves sold through conventional and special auctions at the Keady Livestock Market during the fall of 1999 and 2000.


METHODS
Buyers of calf groups were approached at the auction market or contacted by telephone and asked to record the number of calves requiring treatment for bovine respiratory tract disease (BRD) during the first 28 days after purchase.


RESULTS
211 calf groups (> or = 20 calves/group) were followed up for 28 days after purchase. Multivariate logistic analysis indicated that vaccinated calves purchased through special auctions were 0.68 (95% confidence interval, 0.50 to 0.93) times as likely to receive treatment for BRD as were calves purchased at conventional auctions and that conditioned calves were 0.22 (95% confidence interval, 0.12 to 0.38) times as likely to receive treatment. Groups that received antimicrobials by injection on arrival at the feedlot were 0.64 (95% confidence interval, 0.43 to 0.96) times as likely to be treated as were groups that did not.


CONCLUSIONS
Results suggest that vaccinated and conditioned calves were less likely to receive treatment for BRD during the first 28 days in the feedlot; however, there was no difference in mortality rate.
Macartney
Joanne E
JE
Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON Canada N1G 2W1.
Bateman
Kenneth G
KG
Ribble
Carl S
CS
D000822:Animal Husbandry / Q000191:economics*; D000818:Animals; D001947:Breeding / Q000191:economics; D002417:Cattle / Q000502:physiology; D002418:Cattle Diseases / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D015331:Cohort Studies; D005260:Female; D006304:Health Status; D008297:Male; D009017:Morbidity; D015999:Multivariate Analysis; D009864:Ontario; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000401:mortality / Q000662:veterinary*; D014611:Vaccination / Q000191:economics / Q000662:veterinary*