Variance and covariance components were estimated for yearling scrotal circumference and weaning weight from Limousin field data. Records of 8.226 bulls were used to evaluate 584 sires and 653 maternal grandsires. Data included all herdbook records of bulls with a recorded scrotal circumference and their weaning contemporaries. Analyses were performed by restricted maximum likelihood techniques...

Records of gestation length (71,461) for Simmental cattle were distributed with mean 284.3 d and standard deviation 5.52 d. Gestation length was found to increase with percent Simmental and was 1.9 d longer for calves born to mature dams than for those born to heifer dams. Bull calves experienced gestation lengths 1.5 d longer than heifer calves. Sire, maternal grandsire, residual and total var...

Th e aim of study was to investigate diff erent models for the evaluation of dairy bulls for male fertility. A dataset containing single insemination records performed on Brown Swiss cows and heifers reared in Eastern Italian Alps was used. Th e outcome variable (successful/ unsuccessful) was analyzed as binary trait. In the fi rst step raw conception rate was computed for each service sire, as...

Scientific data for carcass traits of terminal-sire sheep breeds can be used to improve the value of market lambs, but information is lacking for modern terminal-sire breeds in the United States. Thus, the effects of terminal-sire breed on 14 fabricated carcass measurements were determined in F1 wether lambs. Columbia, USMARC-Composite (Composite), Suffolk, and Texel rams were mated with mature...

Analysis of variance (ANOVA) and symmetric differences squared (SDS) methods were used to estimate additive genetic and environmental variances and covariances associated with weaning weight. The two methods were applied to 503 beef records collected over 19 yr from a relatively unselected university Angus herd. The SDS methodology was used with four models. The first model included direct (g) ...

A strategy for simultaneous sire and cow evaluation of genetic merit was implemented. First lactation records of 1,074,971 Holstein cows in 20,065 herds were included. After inclusion of ancestors, there were 1,741,356 equations: 1,505,938 cow, 229,394 herd-year-season, 6000 sire, and 24 genetic group equations. All known genetic relationships among animals were considered. Genetic group coeffi...

A joint sire and cow evaluation for selected type traits has been carried out for the Canadian Holstein population using an individual animal model accounting for all known relationships. Only first lactation, first classification linear records were utilized. Linear scores for final class/final score (combined), feet and legs, mammary system, and stature were analyzed. The model of analysis in...

The nature of the heterogeneity of variance for 200- and 365-d weights by sex, sire breed, and dam breed subclasses was studied. Data consisted of records for weaning (n = 7,829) and yearling (n = 7,367) weights of progeny from 673 and 672 sires, respectively, from 22 breeds that have been evaluated in the Germ Plasm Evaluation Program at the U.S. Meat Animal Research Center, Clay Center, NE. S...

Mortality records of 8,642 lambs from a composite population at the U.S. Meat Animal Research Center during the first year of life were studied using discrete survival analyses. Lamb mortality was studied across periods from birth to weaning, birth to 365 d of age, and weaning to 365 d of age. Animal-time data sets were created for each period using different time intervals: daily, weekly, fort...