Production Losses in Dairy Cattle Due to Days Open
نویسندگان
چکیده
منابع مشابه
Factors affecting days open, gestation length, and calving interval in Florida dairy cattle.
Effects of several factors on reproductive performance were evaluated. Mean performance and number of observations were for days from parturition to first service, 93 and 7730; days from first to successful service, 35 and 11,751; days open, 123 and 8571; gestation length, 280 and 13,612; and calving interval, 400 and 8524. Data covered 52 yr during which no detectable trends in calving interva...
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The aim of this work was to analyse the genetic parameters affecting days open (DO) in beef cattle to evaluate its potential as criterion of selection. The present study characterises DO as a trait with considerable genetic variability, relative to that usually found for reproduction traits, especially for heifers and second calving cows. The estimates of heritability for the trait ranged from ...
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Free radicals are normally produced by living organism, at controlled production rate they perform physiological functions as signal transduction molecules. However, situations leading to an overproduction that surpasses antioxidant capacity creates oxidative stress. Consequently, damage to the cell membrane, protein, DNA and cell death are observed. Dairy cattle are susceptible to oxidative st...
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a data file containing 607662 (317608) milk (open days) records belonging 294417 (177838) holstein cows that were calved from 1983 to 2008 was used. the bivariate repeatability model was used for data analyzing so that herd, calving year, calving month, days in milk (only for milk trait) and calving age for each parity, were assumed as fixed effects and additive genetics and permanent environme...
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the objective of this study was to estimate genetic parameters coupled with genetic and phonotypic trends for age at first calving (afc), open days(od) and milk yield(my) of first lactation in iranian holstein cows. records of reproduction and production for genetic evaluation from 1984 to 2005 for afc, od and my were 71736, 20126 and 20126, respectively. single and two-variable animal models w...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1968
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(68)87031-6