Genetics and Breeding (Online Only): Estimation of (Co) variance Function coefficients For Test Day Yield with a Expectation-Maximization Restricted Maximum Likelihood Algorithm

摘要

Coefficients for (co) variance functions were ob- tained via random regression models using the expectation-maximization REML algorithm. Data in- cluded milk, fat, and protein yields from 176, 495 test days of 22, 943 first lactation Holstein cows that calved in Pennsylvania and Wisconsin from 1990 through 1996. Three approximately equal-sized data sets were created: one for Pennsylvania and two for Wisconsin. Random regressions were on third order Legendre polynomials.