Genotype-environment interaction for age at first calving in Holstein cows in Brazil
نویسندگان
چکیده
منابع مشابه
Genetic Parameter Estimates for Lactation Curve Parameters, Milk Yield, Age at First Calving, Calving Interval and Somatic Cell Count in Holstein Cows
The objective of this study was to estimates the genetic and environmental components for the lactation curve parameters, milk yield, age at first calving (AFC), calving interval (CI) and somatic cell count (SCC) in Iranian Holstein cows. The dataset consisted of 210625 test day records from 25883 cows with milk yield in the first parity recorded from July 2002 to September 2007 in a total of 9...
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...
متن کاملphenotypic 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 کاملGenetic (Co)variance between Age from First to Third Calving and Milk Yield of Holstein Cows in the Tropics
A total of 245187 records of the first three lactations of 131126 Holstein cows in tropical conditions were used to estimate the genetic (co)variance components between age at calving and its respective milk productions. A multivariate analysis of six traits was performed. Heritability for age at calving (h2AC) and milk yield (h2MY) decrease from the ...
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ژورنال
عنوان ژورنال: Veterinary and Animal Science
سال: 2020
ISSN: 2451-943X
DOI: 10.1016/j.vas.2020.100098