Journal article
Use of survival analysis to compare cull rates between bovine leukemia virus seropositive and seronegative dairy cows
American journal of veterinary research, Vol.54(9), pp.1400-1403
09/1993
Handle:
https://hdl.handle.net/2376/113288
PMID: 8239124
Abstract
Bovine leukemia virus (BLV) infection and culling of cows in a commercial dairy herd were evaluated to determine whether a relation existed between the 2 factors. Cattle from the study population, a Holstein dairy herd consisting of approximately 400 milking cows, were tested for antibodies to BLV, using the agar gel immunodiffusion test, semiannually for 2 years, annually for 2 years, and when cattle were culled. Complete records of BLV test results were available for 849 (79%) of the 1,078 cattle that had at least 1 test during the study period. Using the Cox hazard model, the cull hazard rates (culls/cow-months) were greater for BLV seropositive cows than for seronegative cows > 36 months old. Hence, among older dairy cows, BLV-infected cows were culled prematurely, compared with uninfected cows.
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Details
- Title
- Use of survival analysis to compare cull rates between bovine leukemia virus seropositive and seronegative dairy cows
- Creators
- F L Pollari - Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle 98195R F DiGiacomoJ F Evermann
- Publication Details
- American journal of veterinary research, Vol.54(9), pp.1400-1403
- Academic Unit
- Veterinary Clinical Sciences, Department of
- Publisher
- United States
- Grant note
- CA09168 / NCI NIH HHS
- Identifiers
- 99900547747201842
- Language
- English
- Resource Type
- Journal article