the main objective of this study was to estimate the genetic parameters for multi-trait evaluation of birth weight (bw), gestation length (gl) and calving difficulty (cd) in first-parity iranian holstein dairy cattle. the data included 29,950 calving records collected during 1995 to 2014 by the animal breeding and improvement center of iran. a threshold-linear sire-maternal grandsire model was ...

Heritabilities of and genetic correlations between additive direct and maternal genetic effects for calf market weight, and additive direct genetic effects for carcass traits, were estimated for Japanese Black cattle by REML procedures under 2-trait animal models. Data were collected from calf and carcass markets in Hyogo and Tottori prefectures and analyzed separately by prefecture. Calf marke...

___________________________________________________________________________________ Abstract The data used for this study consisted of 27 485 kid records, the progeny of 599 sires and 10 077 dams, and were collected on the 2000to 2009-born kids of 11 Angora goat studs. Variance and covariance components and ratios pertaining to direct additive genetic variation, maternal additive genetic variat...

Estimates of covariance components were obtained for milk production of beef cows, measured by the weigh-suckle-weigh method, and weaning weight and preweaning growth of their calves for a herd of Polled Herefords and a herd of a multibreed synthetics, so-called Wokalups. Analyses were carried out by restricted maximum likelihood fitting an animal model incorporating both direct and maternal ge...

For models with only additive direct genetic effects, the rules of Westell combined with the Q-P transformation can be used to calculate the coefficients of mixed-model equations corresponding to the inverse elements of the numerator relationship matrix and group effects that are used to account for selection on ancestors that do not have records. Groups generally can be assigned on the basis o...

For models with only additive direct genetic effects, the rules of Westell combined with the Q-P transformation can be used to calculate the coefficients of mixed-model equations corresponding to the inverse elements of the numerator relationship matrix and group effects that are used to account for selection on ancestors that do not have records. Groups generally can be assigned on the basis o...

Genetic evaluations in Brazil are performed within each animal breed; however, with the wide range of extant genetic groups in the country and the increased use of genetic crossing as a form of rapid meat production, more elaborate programs that can jointly evaluate animals of different genetic groups are needed. Genetic evaluation of a composite breed is difficult because of the variation in t...

Effects of nine generations of 450r per generation of ancestral spermatogonial X irradiation of inbred rats on genetic parameters of body weight at 3, 6, and 10 weeks of age and of weight gains between these periods were studied. Covariances among relatives were estimated by mixed model and regression techniques in randomly selected lines with (R) and without (C) radiation history. Analyses of ...