Strong legs and feet give longer herd life of dairy cows. Therefore, many countries include measures of leg and feet conformation traits in their breeding programs, often as early predictors of longevity. Five leg conformation traits were measured on grand-daughters of 19 Danish Holstein sire families with 33 to 105 sons. The traits measured were: rear legs side view, rear legs rear view, hock ...

Telegony is the belief that the sire first mated to a female will have an influence upon some of that female's later offspring by another male. Although the reality of telegony was acknowledged by such authorities as Darwin, Spencer, Romanes and many experienced breeders, it has been met with scepticism because of Weismann's unfavourable comments and negative results obtained in several test ex...

The Global Health 2035 report notes that the "grand convergence"--closure of the infectious, maternal, and child mortality gap between rich and poor countries--is dependent on research and development (R&D) of new drugs, vaccines, diagnostics, and other health tools. However, this convergence (and the R&D underpinning it) will first require an even more fundamental convergence of the different ...

Frequency of abortions recorded through Dairy Herd Improvement (DHI) testing was summarized for cows with lactations completed from 2001 through 2009. For 8.5 million DHI lactations of cows that had recorded breeding dates and were >151 d pregnant at lactation termination, the frequency of recorded abortions was 1.31%. Effects of year, herd-year, month, and pregnancy stage at lactation terminat...

Numerous meat sheep breeding programs in developed and developing countries are characterized by incomplete sire information a predominant use of natural matings. These two parameters potentially affect the benefit genomic selection (GS), especially for late-in-life trait. Using stochastic simulations, genetic gains obtained using conventional strategies maternal trait were evaluated population...

Multiple regression of genetic evaluations for milk yields of first lactations of 159 Holstein bulls on sire, dam, and maternal grandsire evaluations indicates that the weight for estimated transmitting ability of the dam calculated from the first record of the dam and first records of her herdmates is about as theoretically expected and is markedly superior both to estimated transmitting abili...

The objectives of this research were to assess the utility of multiple services, rather than first service only, and an expanded service sire term for prediction of bull conception rate (CR) by artificial insemination in the United States. The intent with the expanded service sire term was to determine whether accuracy could be improved by estimating factors affecting the bull's CR explicitly i...

Data from 2,089 laboratory rats utilized in selection experiments were used to estimate maternal influence on growth from weaning (21 d) to 16 wk of age. Adjustment factors were calculated for the effects of sex, generation, litter size, inbreeding of the dam and inbreeding of the offspring on the body weights. The effect of line of sire was included in the analysis of variance models. Covarian...

Heat stress has negative effects on pregnancy rates of lactating dairy cattle. There are genetic differences in tolerance to heat stress; Bos taurus indicus (B. t. indicus) cattle and embryos are more thermotolerant than Bos taurus taurus (B. t. taurus). In the present study, the effects of sire and sire breed on conception and embryonic/fetal loss rates of lactating Holstein cows during the Br...

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 ...