Data from the first four parities of Large White pigs were used to estimate (co)variance components and genetic parameters for litter size (LS) in single trait and multi-trait analyses. The (co)variance components and genetic parameters were estimated by restricted maximum likelihood using the MTDFREML program. LS in each parity was considered a different trait and the models included contemporary group as fixed effect and additive direct genetic and residual as random effects. Heritability estimates of LS in different parities in […]

Data from 12.840 litters, recorded from 1989 to 2003, were used to evaluate genetic parameters and genetic trends of reproductive traits in Large White pigs. Data were provided by the Swine Breeders Brazilian Association – ABCS and included records on litter size at birth (NLN), litter size at 21 days (NLD), average litter weight at birth (PMNasc), litter weight at weaning adjusted to 21 days (PMD), average daily weight gain (GMD) and number of stillbirth (NatMort). Variance components were estimated […]

The aim of this study was to evaluate the influence of environmental factors and to estimate the heritability of weaning-estrus interval in Dalland (C-40) sows in the Southeast of Brazil. Data consisting of 1,032 weaning-estrus intervals recorded in two herds were analyzed by a model that included the random effects of sire and dam and the fixed effects of year of farrowing, herd and the farrowing season, and the covariables age of sow at farrowing, litter size at birth and […]

The additive and non-additive effects on pre-weaning and post-weaning traits in Hereford x Nelore animals were estimated by multivariate linear regression analyses, including or not the ridge regression procedure. Variance inflation factors (VIF) estimates for all covariates were larger in the analysis without ridge regression. The estimates obtained in this study were used to predict the performances of successive generations of a ½ crossbred Braford population resulting from mating Hereford bulls to Nelore cows. High performance was observed in the […]

The objectives of this study were to map Quantitative Trait Loci (QTL) in chromosomes 16, 17 and 18 and to associate their effects with performance traits in a F2 pig population developed by mating two Brazilian Piau sires with 18 crossbred dams (Landrace x Large White x Pietrain). The linkage map for this population was constructed after genotyping the animals for 11 microsatellite markers and scoring the genotype. Estimates of polymorphic information content (PIC) indicated that the microsatellite markers were […]

Records from 2.440 first lactations of Gir cows, calving between 1990 and 2005, were used for estimating genetic parameters of test-day milk yield (TDMY) and accumulated 305 day milk yield (M305) in univariate and bivariate animal models analyses. The model for TDMY included the contemporary group (CG) defined by the combination of herd, year and season of test day, the class of age of cow at calving and the linear covariate of days in milk (linear regression) as fixed effects […]

Random regression and Legendre polynomial (LP) of different orders were used for modeling the genetic, permanent environmental and residual variances of test day milk yield in dairy goats. The models included the fixed effects of contemporary group, age of dam at kidding as a covariate and the fixed regression of LP for the average lactation curve and the additive genetic, permanent environmental and residual as random effects. According to the values of the logarithm of the likelihood function, AIC and […]

This study was aimed at defining profitability measures designed for prediction of breeding values (EBV) in dairy cows. Performance and economic data recorded in herds enrolled in the DHIA (Dairy Herd Improvement Association) program in Kentucky, USA, were used to evaluate economic functions which included the following profitability measures: lifetime net income (LNI), efficiency (EF), milk income over feed costs (IOFC), net income per day of productive life (NIPL), net income at the end of the first lactation (NI1), and […]

The objectives of this study were to evaluate reproductive traits (age at first calving and calving interval) and to obtain heritability estimates for birth weight in a crossbred (Murrah and Mediterranean breeds) Buffalo population in Rondonia State, Brazil. Data recorded between 1979 and 2001 were analyzed by SAS®. Variance components and heritability estimates were obtained by using the DFREML program. Age at first calving (1,291 ± 235 days) was significantly influenced by the contemporary group of dam. Calving interval (451 […]

The goals of this research were to obtain genetic parameters and estimate genetic trends in Landrace pigs. Data consisted of records from 927 granddams, 2,537 dams and 8,887 litters raised in the state of Rio Grande do Sul, Brazil, provided by the Swine Breeders Brazilian Association ABCS. Variance components were estimated by REML, using a model that included the direct genetic effect, maternal effect, common litter effect and the fixed effect of contemporary group. Contemporary groups were defined as a […]