Data from 3,593 beef heifers and 4,079 of their steer paternal half-sibs were used to estimate genetic parameters of and among female growth and reproductive traits and male carcass traits. Estimates of heritability for adjusted 205-d weight, adjusted 365-d weight, age at puberty, calving rate, and calving difficulty measured on females were .16, .38, .47, .19, and .18, respectively; estimates ...

The aim of this study was to estimate direct and maternal genetic parameters for calving difficulty score, stillbirth, and birth weight at first and later parities for Charolais and Hereford cattle in Sweden. Calving traits have long been recorded for pure-bred beef cattle in Sweden, but only birth weight has been used in the selection in order to avoid calving difficulties. Linear animal model...

The effect of growth rate from birth through 30 months of age on the reproductive performance of Polled Hereford heifers calving as 2-year-olds was examined. Heifers with high gains during the first winter as weanlings had higher breeding efficiency when bred as yearlings, had larger pelvic areas as 2-year-olds, gave birth to larger calves, had less calving difficulty at first parturition and h...

the purposes of this study were to estimate the effects of risk factors on stillbirth parturition and evaluatethe effects of stillbirth on lactation performance in holstein dairy cows. data were obtained from a dairycattle herd located in isfahan province, iran. the logit of the probability of stillbirth was modeled usinglogistic regression and the effect of stillbirth on lactation performance ...

OBJECTIVE Calving ease (CE) is a complex reproductive trait of economic importance in dairy cattle. This study was aimed to investigate the genetic merits of CE for Holsteins in Korea. METHODS A total of 297,614 field records of CE, from 2000 to 2015, from first parity Holstein heifers were recorded initially. After necessary data pruning such as age at first calving (18 to 42 mo), gestation ...

This 4-yr study was conducted with Angus (A)-sired and Polled Hereford (PH)-sired crossbred heifers that were exposed to either A or medium-frame Brahman (B) bulls from primiparous calvings either as 2- or 3-yr-olds. Each year, heifers were allotted at random within breed composition and age of dam to breeding groups on pasture for an 84-d breeding period that began in late March or early April...