Genetic Correlations between Days to Calving across Joinings and Lactation Status in a Tropically Adapted Composite Beef Herd

Estimates of Genetic Correlations between Live Ultrasound Scan Traits and Days to Calving in Hereford Cattle

Restricted maximum likelihood estimates of genetic correlations between between live ultrasound scan measurements and days to calving were obtained from bivariate analyses. Scan traits considered were fat depth at the 12/13−th rib, P8 fat depth, percentage intramuscular fat and eye muscle area, treating records for heifers or steers and bulls as separate traits. Analyses were carried out includ...

Genetic Relationship between Milk Yields, Calving Ease and Days Open at First Lactation of Holstein Cows in Korea

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...

Across-Herd Genetic Evaluations

Currently in Australia, there are two main ways to compare animals from different herds. The first is to buy animals or semen from other breeders and test their progeny on-farm against "home-bred" animals. The second is to enter animals in a central testing facility, such as WACOL, SABOR or TOCAL. Both of these methods can be subject to sampling problems or, in other words, chance, that can aff...

Relationship between Scrotal Circumference, Quantitative Testicular Traits and Growth Performance in Tropically Adapted Yearling Beef Bulls Differing in Age

A Preliminary Estimate of the Heritability of Uterine Cervical Diameter in Tropically Adapted Beef Cattle

Mean uterine cervical diameter, parity and parentage information was recorded from 246 Santa Gertrudis females in southern Queensland. A linear model was fitted to estimate the effects of parity on cervical diameter. The sire variance component was also analysed to provide an estimate of the heritability of cervical size. The effect of parity on cervical size was found to be highly significant ...