Twelve Hereford bulls were used to sire calves in each of three locations in North Carolina over 6 yr. Three bulls were bred artificially to a random one-third of the cows at each location each year. Locations represented the Mountain, Piedmont and Coastal Plain regions of the Southeast. As yearlings, steer progeny were fed a concentrate diet in a feedlot or grazed on pasture and then slaughter...

The objective was to determine appropriate analytical models considering cytoplasmic inheritance for birth weight (BWT, n = 35,604), weaning weight (WWT, n = 34,114), fleece weight (FWT, n = 38,113) and number born (NB, n = 39,029) for Rambouillet sheep. For BWT, models that included dam by year, dam by number born, and sire by dam effects, in addition to direct and maternal effects, were signi...

The objective of this study was, by means of simulation, to quantify the effect of ignoring individual heterogeneity in Weibull sire frailty models on parameter estimates and to address the consequences for genetic inferences. Three simulation studies were evaluated, which included 3 levels of individual heterogeneity combined with 4 levels of censoring (0, 25, 50, or 75%). Data were simulated ...

The objectives of this experiment were to characterize longissimus muscle color, texture, and firmness for beef carcasses of diverse biological types and to determine the genetic parameters of lean color, texture, and firmness. The carcasses (n = 3,641) used in this experiment were from steers produced by mating Angus, Brahman, Braunvieh, Charolais, Chianina, Galloway, Gelbvieh, Hereford, Jerse...

The genetic model for fetal effect on production of the dam is described, and studies on genetic and economic implications are reviewed. The effect on production from the sire of the cowhas 1.58 to 3.02 times as much economic value as the effect from the sire of the fetus. The use of mate records in evaluating a sire in addit ion to daughter records could increase economic gain from selection b...

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 ...

Gestation length, birth weight calving difficulty, calf mortality rate at birth, calf mortality rate from birth to weaning, preweaning calf growth rate and calf 200-d weight were evaluated in a biological type study in which four sire breeds were bred by AI to Hereford dams. Angus and Red Poll sires represented breeds of medium size, and Pinzgauer and Simmental sires represented large breeds. A...