Records of mortality during the first year of life of 8,642 lambs from a composite population at the U.S. Meat Animal Research Center were studied using survival and logistic analyses. The traditional logistic approach analyzes the binary response of whether or not a lamb survived until a particular time point, thus disregarding information on the actual age at death. Survival analysis offers a...

Milk yield, fat yield, and fat percentage during the first three lactations were studied using New York Holsteins that were milked twice daily over a 305-d, mature equivalent lactation. Those data were used to estimate variances from direct and maternal genetic effects, cytoplasmic effects, sire by herd interaction, and cow permanent environmental effects. Cytoplasmic line was traced to the las...

Materials and methods: Gilt and boar progeny from 8276 litters of a genetic multiplier that used four dam lines and fi ve sire lines were observed for umbilical hernias by 11 weeks of age. Hernias were attributed to birth litter. Odds of umbilical hernia development were calculated using logistic regression and rates were calculated using Poisson regression. Negative binomial models using sire ...

in order to study on the effect of incomplete sire's pedigree on the prediction of breeding value and estimation of genetic trend, two quantitative traits such as weaning weight and average daily gain with heritabilities 0.15 and 0.30 were simulated. phenotypic, genetic and environmental correlations were assumed 0.5. resulted data files with different proportion of missed sire pedigree (0...

Maximum likelihood methods for the estimation of linkage disequilibrium between biallelic DNA-markers in half-sib families (half-sib method) are developed for single and multifamily situations. Monte Carlo computer simulations were carried out for a variety of scenarios regarding sire genotypes, linkage disequilibrium, recombination fraction, family size, and number of families. A double hetero...

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...

OBJECTIVE This study was conducted to estimate breed-specific variance components for total number born (TNB), number born alive (NBA) and mortality rate from birth through weaning including stillbirths (MORT) of three main swine breeds in Korea. In addition, the importance of including maternal genetic and service sire effects in estimation models was evaluated. METHODS Records of farrowing ...

A method of storing and retrieving nonzero elements of a large, sparse symmetric matrix using only internal computer storage is presented. An algorithm for applying the recursive or tabular method of calculating the numerator relationship matrix of a large group of animals is given. The algorithm is applicable to inbred and noninbred populations and can be used on sire/dam or sire/maternal gran...