Age at first calving in dairy cows: which months do you aim for to maximise productivity?
نویسندگان
چکیده
منابع مشابه
phenotypic and genotypic analysis of age at first calving in iranian holstein dairy cows
introduction: age at first calving (afc) has an important effect on profitability and reproductive management of dairy cattle. every month increase in afc beyond 24 months increases the cost of production. the time between birth and first calving represents a period in which replacement heifers are not generating income. instead this rearing period requires considerable capital expenditures inc...
متن کاملEstimation of Genetic and Phonotypic Trends for Age at First Calving, Calving Interval, Days Open and Number of Insemination to Conception for Isfahan Holstein Cows
For the current research the records of 62 farms in Isfahan province were available. To estimate genetic and phonotypic trends of reproductive traits such as age at first calving, calving interval, days open and number of insemination to conception rate the records of 63,866 cows including 167793 reproductive records were employed. Farms were covered by Vahdat industrial Agriculturists and Dair...
متن کاملEstimation of Genetic and Phonotypic Trends for Age at First Calving, Calving Interval, Days Open and Number of Insemination to Conception for Isfahan Holstein Cows
For the current research the records of 62 farms in Isfahan province were available. To estimate genetic and phonotypic trends of reproductive traits such as age at first calving, calving interval, days open and number of insemination to conception rate the records of 63,866 cows including 167793 reproductive records were employed. Farms were covered by Vahdat industrial Agriculturists and Dair...
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The term "learning styles" refers to the concept that individuals differ in regard to what mode of instruction or study is most effective for them. Proponents of learningstyle assessment contend that optimal instruction requires diagnosing individuals' learning style and tailoring instruction accordingly (pashler, McDaniel, Rohrer, and Bjork, 2009). There are several methods or theories that d...
متن کاملGenetic 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: Veterinary Evidence
سال: 2020
ISSN: 2396-9776
DOI: 10.18849/ve.v5i1.248