Genetic Parameters of Milk Yield and Milk Fat Percentage Test Day Records of Iranian Holstein Cows
نویسندگان
چکیده
منابع مشابه
Estimation of Genetic Parameters for Milk Production Trait in Holstein Cows of the Mazandaran Gavdasht Herd Using Test Day Records
Random regression models (RRM) are used for genetic estimations of milk traits in dairy cows. RRM utilize data on traits that are repeated during the time, such as milk trait, which allows of the evaluation of the test day production information. In this study, to estimate genetic parameters for milk production trait, test day records (TDR) were collected from the first lactation of Holstein co...
متن کاملGenetic Analysis of Milk Yield in Iranian Holstein Cattle by the Test Day Model
Using monthly test day records the genetic parameters of Iranian Holstein cattle in first lactation were studied. Data of 277400 test-day milk records from 65320 cows and 2210 sires were analyzed by an animal random regression model using restricted maximum likelihood methodology. The model included herd-test-date, interaction between year-season of calving, days in milk (linear and quadratic) ...
متن کاملEstimation of Genetic Parameters and Genetic Trends of Somatic Cell Score in Iranian Holstein Cows Using Test-Day Records
The aim of the present study was to estimate the genetic parameters and genetic trends of somatic cell score (SCS) in the first 3 lactations of Iranian Holstein cows by random regression (RR) animal model by using Restricted Maximum Likelihood (REML) method. The data set used in this analysis included observations of 340318 test-day records of 41526 cows in 288 herds; 89969 test-day of 11750 co...
متن کاملDefining appropriate model for genetic analysis of milk yield in different lactations of Iranian Holstein cows
In this study, appropriate genetic co (variance) structure across ages of milk production in the Iranian Holstein cows was modeled using 35167 records originated from 1098 sires and 27236 dams. These data were collected from 110 herds during 2011 to 2015 by the Iranian Animal Breeding Center. For all lactations, birth year, birth month, calving year, calving season, calving month, age and herd ...
متن کاملestimation of genetic parameters for milk yield using random regression test day model in iranian holstein
in this study a total of 171,360 monthly test day milk records obtained from first lactation of iranian holstein cattle (three times a day milking) distributed in 96 herds and calved from 1999 to 2008 were used to estimate genetic parameters and to predict breeding values of the animals. the data was analyzed using random regression test day model. the results showed that average of heritabilit...
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ژورنال
عنوان ژورنال: Asian-Australasian Journal of Animal Sciences
سال: 2005
ISSN: 1011-2367,1976-5517
DOI: 10.5713/ajas.2005.1231