The objective of this research was to compare the magnitude of genetic parameters (coefficients of heritability and genetic correlation) as estimated by the Restricted Maximum Likelihood (REML) method and Bayesian Inference, and to estimate the genetic and phenotypic trends to the traits height at the withers (HW24) and weight at 24 months of age (W24). The average heritability estimated by Bayesian Inference to HW24 was 0.47, and it was lower than that obtained by REML bi-trait analysis (0.52); however, the […]

The objectives of this study were to estimate heritabilities and genetic and phenotypic correlations between carcass traits measured by ultrasound and other economically important traits generally used as selection criteria in beef cattle and to estimate the genetic changes in the carcass traits as a result of selection for post-yearling weight. Carcass traits measured by ultrasound at two ages (12 and 18 months) and the correlation of these traits with weight, hip height and body condition score of males (yearling) […]

The objective of this study was to obtain estimates of genetic and phenotypic parameters for egg mass of meat quails and also to propose an optimal age for selection of birds through the egg mass. The data used in this study came from 3,503 female meat quails (UFV1: 1.811 quails; UFV2: 1.692 quails) of the Poultry Breeding Program from Universidade Federal de Viçosa. The traits examined were egg mass in partial periods until 77, 112, 147 and 182 days, and […]

The objective of this study was to characterize the population genetic structure of the Gir breed in the Northeast of Brazil. The data used in this study were taken from pedigree information of 8,897 Gir animals between 1957 and 2007, obtained from the Brazilian Zebu Breeders Association (ABCZ). The program ENDOG was used to estimate the parameters based on the probability gene origin. From the amount of the studied animals, 67.22%, 18.41% and 3.15% had complete pedigree only on the […]

The objective of the present study was to analyze models with genetic and/or residual heteroskedasticity for genetic evaluation of the weaning weight of Charolais-Zebu crossbred calves. Weaning weight data from 56,965 crossbred calves were analyzed using animal models with different combinations of genetic and residual heteroskedasticity and/or homoskedasticity. The inference on a posteriori distributions of genetic parameters were by the Monte Carlo method via Markov chains. The model with genetic and residual heteroskedasticity was the best fit on the data. […]

The objective of this study was to investigate, in a population of crossbred cattle, the obtainment of the non-additive genetic effects for the characteristics weight at 205 and 390 days and scrotal circumference, and to evaluate the consideration of these effects in the prediction of breeding values of sires using different estimation methodologies. In method 1, the data were pre-adjusted for the non-additive effects obtained by least squares means method in a model that considered the direct additive, maternal and […]

The objective of this study was to evaluate selective mating using distribution of extremes, among other mating strategies, on its ability to decrease the endogamy and the loss of genetic variability. The genetic simulation system (Genesys) was used to simulate two genomes (each one with a single characteristic whose distinction was the value of heritability) and the base and original populations. Each initial population was submitted to assisted selection by markers for ten consecutive generations. For evaluation of strategies, the […]

In order to determine the profile of leptin and insulin values in seminal plasma and their correlations with sperm patterns during the peripuberty, a total of 16 crossbred Gyr dairy bulls were monitored from 60 days before to 60 days after puberty, separated into two groups, early and regular, according to the onset of puberty. Hormone values were determined by radioimmunoassay after gel filtration in fast performance liquid chromatography and semen patterns, according to the Brazilian College of Animal Reproduction. […]

The objective of this study was to verify the effect of three protocols of cryopreservation on the sperm viability post-thawing of swine from the Piau breed (Sus scrofa), by means of evaluation assays in vitro and in vivo. Twenty-two ejaculates of 5 adult males of the Piau breed trough the gloved-hand method. In order to verify the sperm viability of the raw semen and post-thawing, the following traits were evaluated: sperm motility and vigor, hypoosmotic test, supra-vital color test and […]

The objective of this study was to estimate heritability and verify the genetic correlations between heifers subsequent rebreeding with weaning hip height (WHH) and yearling hip height (YHH), using Bayesian inference. The (co)variance components and genetic parameters were estimated using an animal nonlinear (threshold) model for subsequent rebreeding and an animal linear model for WHH and YHH. The animal model included the contemporary group as the systematic effect and direct additive genetic and residual effects as random effects. Genetic maternal […]