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 ...

in this study records of 15723, 12108 and 5236 zel sheep for birth weight (bw), weaning weight (ww) and 6-month weight (6mw) traits were used. data has been collected by the jahad-e-keshavarzi organization of province of mazandaran during 1994-2009. the heritability of direct and maternal of growth traits was estimated using the univariate analysis with restricted maximum likelihood (reml). in ...

The aim of this study was to model the variances and covariances of body weight in Zandi sheep from 60 to 365 days of age using random regression models (RRM). Legendre polynomials of different orders were used to model the direct and maternal covariances. Mean trends were also modeled through a quadratic regression on orthogonal polynomials of age. Homogeneity and heterogeneity of the residual...

(Co)variance components, direct and maternal breed additive, dominance, and epistatic loss effects on preweaning weight gain of beef cattle were estimated. Data were from 478,466 animals in Ontario, Canada, from 1986 to 1999, including records of both purebred and crossbred animals from Angus, Blonde d'Aquitaine, Charolais, Gelbvieh, Hereford, Limousin, Maine-Anjou, Salers, Shorthorn, and Simme...

due to cereal are affected by drought stress in their lifetime. in order to study gene action of bread wheat under drought stress condition, a generation mean analysis was performed using f1, f2 and f3 generations derived from roushan and kavir. generation mean analysis was performed based on joint scaling test. genetic parameters including additive effect (d), dominance effect (h), additive×ad...

Data containing 14,188 lactation and reproductive records of Korean Holstein cows at first parity distributed across 3734 herd-year-season groups were analyzed to get genetic (co)variance estimates for milk yield, fat yield, calving ease, and days open. Milk and Fat yields were adjusted to 305 d. Heritabilities and genetic correlations were estimated in two different animal models on which were...

Data containing 14,188 lactation and reproductive records of Korean Holstein cows at first parity distributed across 3,734 herd-year-season groups were analyzed to get genetic (co)variance estimates for milk yield, fat yield, calving ease, and days open. Milk and Fat yields were adjusted to 305 d. Heritabilities and genetic correlations were estimated in two different animal models on which wer...

Estimates of covariances and sire expected progeny differences of additive and nonadditive direct and maternal genetic effects for birth and weaning weights were obtained using records from 1,581 straightbred and crossbred calves from the Angus-Brahman multibreed herd at the University of Florida. Covariances were estimated by Restricted Maximum Likelihood, using a Generalized Expectation-Maxim...

The objective of this study was to estimate (co)variance components using random regression on B-spline functions to weight records obtained from birth to adulthood. A total of 82 064 weight records of 8145 females obtained from the data bank of the Nellore Breeding Program (PMGRN/Nellore Brazil) which started in 1987, were used. The models included direct additive and maternal genetic effects ...