A Cox proportional-hazards model with time-dependent covariates to evaluate the relationship between body-condition score and the risks of first insemination and pregnancy in a high-producing dairy herd
Autor: | Ynte H. Schukken, Witaya Suriyasathaporn, A. Brand, S.J. Dieleman, E.N. Noordhuizen-Stassen, Mirjam Nielen |
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Rok vydání: | 1998 |
Předmět: |
Male
Time Factors Health Status Ice calving Insemination Animal science Food Animals Pregnancy Animals Lactation Medicine Dairy cattle Proportional Hazards Models business.industry Proportional hazards model Data Collection Postpartum Period Milk fever medicine.disease Mastitis Herd Pregnancy Animal Cattle Female Animal Science and Zoology business |
Zdroj: | Scopus-Elsevier |
ISSN: | 0167-5877 |
DOI: | 10.1016/s0167-5877(98)00100-7 |
Popis: | The objective of this study was to determine the relationship between body-condition score and postpartum reproductive efficiency in dairy cattle. Data on body-condition score, reproduction, diseases, and production from 1404 lactations of 639 cows, calving between January 1984 and November 1996 on a commercial farm, were used. The Cox proportional-hazards model with time-dependent covariates was used to qualify the relationship between body-condition score on a scale of 1 to 5 and risks of first insemination and pregnancy. Cows with body condition at calving |
Databáze: | OpenAIRE |
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