Sire by Herd Environment Interaction for Milk Production
نویسندگان
چکیده
منابع مشابه
Heritability estimates of milk production with different numbers of records per sire by herd subclass.
The first-lactation milk records of 20,850 artificially sired Holstein cows and their darns were analyzed by a sire-by-herd, variance components model to determine if unequal numbers of records in the filled subclasses had any effect on the paternal half-sib correlatiou or the daughter-dam regression. The variance components were estimated with the number per subclass held constant at 1, 2, 3, ...
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A total of 138,869 lactation milk yields (305 d, milked twice daily, mature equivalent) from the first three parities of 68,063 New York Holstein cows were used to estimate variance components that were due to additive direct genetic effects, cow permanent environmental effects (cow within sire for sire model), sire by herd interaction effects, and cytoplasmic line effects. The original data we...
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The animal model for genetic evaluations of dairy cattle by the USDA currently includes a term for interaction effects of sire and herd. The relative magnitude of the variance of that effect was established in the 1960s as 14% of the total variance, but recent research has shown that the proportion is 2% or less. This report compared EBV using either the 14% or the actual estimate from 20 sampl...
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Received: 7 March, 2014 Accepted: 21 May, 2014 Published: 20 July, 2014 The data consisted of 37118 TD milk record of 5851 primiparous Holstein cows of Tunisia. Herd-years of calving means for milk production traits were clustered in three levels using the CLUSTER procedure in SAS software. Production levels included low, medium and high levels. Genotype by environment interaction were investig...
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Current methods for routine international evaluations are based on pre-processed information. This puts several restrictions on the method of analysis that can be used. For example, comparisons need to be made on genetic evaluation unit bases. Neighboring countries with similar production environments cannot be treated as genetically identical traits, and environmental variation within country ...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1969
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(69)86691-9