Random Regression Test-Day Models with Residuals Following a Student's-t Distribution
نویسندگان
چکیده
منابع مشابه
Analysis of Test Day Milk Yield by Random Regression Models and Evaluation of Persistency in Iranian Dairy Cows
Variace / covariance components of 227118 first lactaiom test-day milk yield records belonged to 31258 Iranian Holstein cows were estimated using nine random regression models. Afterwards, different measures of persistency based on estimation breeding value were evaluated. Three functions were used to adjust fixed lactation curve: Ali and Schaeffer (AS), quadratic (LE3) and cubic (LE4) order of...
متن کاملRobust Lasso Regression with Student-t Residuals
The lasso, introduced by Robert Tibshirani in 1996, has become one of the most popular techniques for estimating Gaussian linear regression models. An important reason for this popularity is that the lasso can simultaneously estimate all regression parameters as well as select important variables, yielding accurate regression models that are highly interpretable. This paper derives an efficient...
متن کاملMultiple Trait Random Regression Test Day Model for Production Traits
Research on test day (TD) models began in Canada in 1991. At that time fixed regressions (within age and season of calving) were used to account for the shape of the lactation curve of dairy cows, but the animal effect was used only to account for differences in height of these curves (Ptak and Schaeffer, 1993). Fixed regression TD model was applied to Canadian dairy goat data (Schaeffer and Su...
متن کاملEfficiency of part lactation test day records for genetic evaluations using fixed and random regression models
The efficiency of part lactation test day (TD) records in first parity for the genetic evaluation of bulls and cows using a random regression model (RRM) and a fixed regression model (FRM) was studied, modelling the random and fixed lactation curves by Legendre polynomials. The data set consisted of 9 242 783 TD records for first lactation milk yield of 1 134 042 Holstein Friesian heifers. The ...
متن کاملEvaluation of Test Day Milk Yield in Iranian Primiparous Holstein Using Different Random Regression Models
Several functions were used to model fixed and random part of the lactation curve in Iranian primiparous Holstein cows using random regression analysis. Legendre polynomials of orders three and four as well as parametric lactation curve for the random part of the first lactation milk production were compared to find the best model. The models differed in fixed regression lactation curve part an...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 2004
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(04)73213-0