Determining the optimum replacement policy for Holstein dairy herds in Iran
نویسندگان
چکیده
منابع مشابه
Optimum Body Size of Holstein Replacement Heifers1
Criteria that define optimum body size of replacement heifers are required by commercial dairy producers to evaluate replacement heifer management programs. Historically recommended body size criteria have been based on live BW measurements. Numerous research studies have observed a positive relationship between BW at first calving and first lactation milk yield, which has served as the impetus...
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Trait-by-trait and multiple trait bioeconomic modeling were used to derive farm-specific economic weights (EW) for a wide range of traits under different production and economic circumstances to define breeding objectives for Holstein dairy cattle in Iran. Production parameters and economic data were gathered on 10 dairy farms from March 2008 to February 2010. The EW (economic values multiplied...
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To describe proportion and pattern of culling in commercial dairy herds of Khorasan Razavi Province, this survey was carried out from 21st March 2008 to 20th March 2009 in 15 industrialized dairy herds. For each culled cow data related to parity at culling, last calving to culling interval and primary reason for culling were recorded. Annual herd exit rate was 20.9%. Out of a total of 652 culle...
متن کاملEstimation of Genetic Parameters for Lactation Curve Traits in Holstein Dairy Cows in Iran
The objectives were to estimate (co)variance components and genetic parameters for lactation curve traits in Holstein dairy cows in Iran. The used data were records on Holstein cows collected during January 2003 to December 2012 by the Animal Breeding Center of Iran (Karaj, Iran). In order to describe the lactation curve, an incomplete gamma function was fitted to 691200 test-day records on 962...
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با توجه به تجزیه و تحلیل داده ها ما دریافتیم که سطح درامد و تعداد نمایندگیها باتقاضای بیمه عمر رابطه مستقیم دارند و نرخ بهره و بار تکفل با تقاضای بیمه عمر رابطه عکس دارند
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 2010
ISSN: 0022-0302
DOI: 10.3168/jds.2009-2765