Genetic parameters for a maternal breeding goal in beef production

摘要: New maternal breeding values have been developed for use in UK beef evaluations. To undertake multitrait BLUP evaluations, it is necessary to a full covariance matrix. This study outlines the approach taken construct matrices four breeds that most widely contribute suckler cows United Kingdom. The traits investigated were age at first calving, calving interval, lifespan, mature cow weight, 200-d and difficulty. Three terminal sire (weight 400 d, ultrasonic fat depth, muscle score) included estimate covariances between new existing traits. A sire-maternal-grandsire model was used estimation procedure series of bivariate multivariate models. weighted bending employed positive definite matrices. Parameter estimates broadly agreed with literature values, although some traits, information very scarce. Some differences parameters different evident.