The objective of this study was to estimate the genetic correlations between visual scores and the carcass traits measured by ultrasound, in Nellore breed cattle, using the bayesian statistics by Gibbs Sampling, in the linear-threshold model. The morphological categorical traits of musculature, physical structure, conformation and sacrum were studied, evaluated at 15 and 22 months. The carcass traits of the longissimus muscle area, backfat thickness, rump fat thickness and hip height were evaluated. Visual scores should be used as selection […]

Variance components (VC) for milk yield of Holstein cows were estimated and the effects of increasing of the number of animals in the numerator relationship matrix (NRM) were evaluated on VC estimates obtained by REML and Bayesian inference via Gibbs sampling (GS). Data were obtained from herds in the states of Minas Gerais, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul. Two data sets were created for each state. In the first set, the NRM included only the […]

The objectives of this study were to estimate the genetic parameters of the following categorical traits: musculature, physical structure, racial breed aspects, conformation, navel, pigmentation and sacrum, and predict breeding values, using bayesian statistics under threshold animal models, considering different ages of cattle of the Nelore breed. The information concerning visual scores were obtained from 2000 to 2005 from cattle of the Nelore breed from thirteen participant farms of the Brazilian Nelore Program. In the two-trait analyses, 500,000 rounds up […]

This study aimed to evaluate the effects of major genes and population size on variance components estimation using four different types of selected populations. Variance components were estimated by classical and Bayesian methodologies, with three a priori information levels. In general, results from REML and Bayesian analyses with flat priors were similar. Except for Bayesian analysis with an informative prior, additive genetic variance estimates were not accurate in populations in which the trait is controlled by major genes. The use […]

A genome of 3.000 centimorgans was simulated for a single quantitative trait governed by 800 loci with two alleles per locus. According to the genomic structure proposed, 1,500 males and 1,500 females constituted the base population which was used to form two (small and large) initial populations. Two types (only additive genetic variance and both additive genetic and environmental variances) and three variability levels (high, medium and low) of heterogeneity of variances were inserted in the initial populations. Variance components […]

The objectives of this study were to estimate phenotypic and genetic parameters for growth traits of meat quails. A total of 1022 birds were housed, identified and individually weighted at 7 days (PES7); 14 days (PES14); 28 days (PES28) and at 42 days (PES42). Covariance components and genetic parameters were estimated by Bayesian procedures using Gibbs sampling with MTGSAM software. Genetic correlations between PES7 and PES14, PES28, and PES42 were respectively 0.73, 0.52 and 0.55 and between PES14 and PES28 […]