Genetic and phenotypic trends for age at first calving and milk yield and compositions in Holstein dairy cows
نویسندگان
چکیده
منابع مشابه
Genetic and phenotypic trends for age at first calving and milk yield and compositions in Holstein dairy cows
Calving records from the Animal Breeding Center of Iran collected from January 1990 to December 2007 and comprising 207 106 first calving events of Holsteins from 2 506 herds were analysed using linear sire models to estimate genetic trends for age at first calving (AFC) and milk traits. Genetic trends were obtained by regressing yearly mean estimates of breeding values on year of birth. In gen...
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ژورنال
عنوان ژورنال: Archives Animal Breeding
سال: 2011
ISSN: 2363-9822
DOI: 10.5194/aab-54-338-2011