Data on Angus (ANG), Charolais (CHR), Hereford (HER) and Limousin (LIM) cattle were used to estimate genetic parameters for calving difficulty (CD) and to quantify genetic relationships among CD, birth weight (BWT) and gestation length (GL). Bayesian analysis was carried out using Gibbs sampling to obtain means of marginal posterior distributions. Estimated heritabilities for direct genetic eff...

Birth weight (BWT) and calving difficulty (CD) were recorded on 4,580 first parity females from the Germplasm Evaluation (GPE) program at the U.S. Meat Animal Research Center. Both traits were analyzed using a bivariate animal model with direct and maternal effects. Genetic groups for breed of AI sire were fitted to estimate breed differences. Bos Indicus influenced breeds tended to have the la...

Reproductive performance of animals affects lifetime productivity. However, improvement of reproductive traits via direct selection is generally slow due to low heritability. Therefore, identification of indicator traits for reproductive performance may enhance genetic response. Previous studies showed that serum IGF-I concentration is a candidate indicator for growth and reproductive traits. T...

The objective of this study was to investigate the importance of maternal genetic effects on postweaning performance traits of Yorkshire, Landrace, Duroc, and Hampshire breeds of swine. Data consisted of performance test records collected in a commercial swine operation from 1992 to 1999. Boars from 60% of the litters were culled at weaning based on a combination of maternal and performance ind...

Weaning weights from nine parental breeds and three composites were analyzed to estimate variance due to grandmaternal genetic effects and to compare estimates for variance due to maternal genetic effects from two different models. Number of observations ranged from 794 to 3,465 per population. Number of animals in the pedigree file ranged from 1,244 to 4,326 per population. Two single-trait an...

introduction: the genetic characterization of local breeds of sheep is of paramount importance, not only for conservation purposes but also for the definition of breeding objectives and breeding programmes. when records are nonexistent and breeds are not well defined in the field, information could be obtained from research station information where pedigree and performance records have been ke...

Few studies have examined the impact of children with genetic disorders and their unaffected siblings on family functioning. In this study, the reciprocal causal links between problem behaviors and maternal distress were investigated in 150 families containing a child with fragile X syndrome (FXS) and an unaffected sibling. Both children's behavior problems appeared to have strong, direct effec...