کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2453302 | 1554222 | 2007 | 9 صفحه PDF | دانلود رایگان |
Our objective of this study was to investigate the relationship between milk urea-nitrogen concentrations ([MUN]) and first-service breeding success (FSBS) in a large number of commercial dairy herds, using various timings on [MUN]. All commercial dairy herds in Prince Edward Island on monthly milk testing (n = 198) formed the sampling frame. Milk components, [MUN], 24-h milk production, and breeding data for all cows from these farms were gathered electronically from a central database. A first service between 1 June 1999 and 31 May 2000 was classified successful (FSBS = 1) if it was the cow's last service and she calved 270–290 d later. Mixed logistic-regression modeling was used to determine the association between FSBS (the outcome variable) and the [MUN] closest to first service, controlling for other possible confounders and clustering effects of cows within the study herds. The final dataset included 2787 successful and 3015 unsuccessful first services. A change in [MUN] on the test closest to first service from 10 to 20 mg/dL was associated with a 13.9% reduction in the odds of FSBS (controlled for parity, milk production and days in milk).
Journal: Preventive Veterinary Medicine - Volume 82, Issues 1–2, 15 November 2007, Pages 42–50