We have used the results of an experiment mapping quantitative trait loci (QTL) affecting milk yield and composition to estimate the total number of QTL affecting these traits. We did this by estimating the number of segregating QTL within a half-sib daughter design using logic similar to that used to estimate the "false discovery rate" (FDR). In a half-sib daughter design with six sire familie...

Several sheep fetuses were thymectomized, and their tails were removed at 58 to 65 days of gestation for tissue culture. Bovine leukemia virus (BLV) antigens were detected in serial culture of tissues from fetuses whose dams and sires were both BLV positive. However, no BLV antigens were detected in serial cultures of tissues from fetuses whose dams were negative but whose sire was positive. Pr...

INTRODUCTION: This study aimed to evaluate a new commercial kit, Kit SIRE Nitratase-PlastLabor, for testing the drug susceptibility of clinical Mycobacterium tuberculosis isolates. METHODS: The accuracy of the Kit SIRE Nitratase was evaluated by examining the susceptibility (streptomycin, isoniazid, rifampicin, and ethambutol) of 40 M. tuberculosis isolates, using the proportion method with L...

The genetic variance of inbred sires is increased and variance due to additive x additive effects proportionately more than that due to additive ones. In case of inbreeding by mating sire to daughters the time interval elite sire – son needs not to be elongated so that the genetic progress could be increased by this procedure. This pertains even more to the procedure where inbred sires are prod...

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 ...

The National Genetic Evaluation Program (NGEP), a project coordinated by the National Pork Producers Council (NPPC) with geneticists and commercial producers in America, provided good evidence for significant differences between terminal sire lines in progeny performance for production, carcase, meat and eating quality traits. The project identified “differences among sire lines for many muscle...

A multivariate linear model was used to estimate sire variance and covariance components and residual variance components for first lactation milk yield and logarithms of yield at three herd production levels using Restricted Maximum Likelihood with the Expectation-Maximization algorithm. Data for four separate analyses were 305-d, mature equivalent first lactation milk records from cows sired ...

Generalized mixed linear, threshold, and logistic sire models and Markov chain, Monte Carlo simulation procedures were used to estimate genetic parameters for calving rate and calf survival in a multibreed beef cattle population. Data were obtained from a 5-generation rotational crossbreeding study involving Angus, Brahman, Charolais, and Hereford (1969 to 1995). Gelbvieh and Simmental bulls si...

The standard of comparison for dairy production records is the 305-day lactation, and much research has been directed to estimating 305-day milk and fat records from incomplete or in-progress records. This study was to determine the effect of several methods of extending incomplete records on sire evaluation. Complete 305-day milk and fat records of first lactations of 73,724 daughters of 1,362...