the aim of this study was to investigate the association of bovine leukocyte antigen-drb3 alleles with peripheral blood mononuclear cell (pbmc) proliferation in response to staphylococcus aureus. the animals included in this study (n=347) were approximately of same age and comprised of f2 holstein-friesian ´ charolais (n = 155), holstein-friesian backcross (f0 holstein-friesian dams crossed wit...

The short interspersed repetitive element (SIRE) of Trypanosoma cruzi was first detected when comparing the sequences of loci that encode the TcP2beta genes. It is present in about 1,500-3,000 copies per genome, depending on the strain, and it is distributed in all chromosomes. An initial analysis of SIRE sequences from 21 genomic fragments allowed us to derive a consensus nucleotide sequence a...

A simulation was carried out to investigate the implementation of a genetic evaluation when the additive relationship matrix is not completely known due to the presence of uncertain paternity in the pedigree. Data were simulated and analyzed using a linear mixed model that included a fixed contemporary group effect plus random additive and residual effects. For the univariate scenario, either 1...

A strategy for simultaneous sire and cow evaluation of genetic merit was implemented. First lactation records of 1,074,971 Holstein cows in 20,065 herds were included. After inclusion of ancestors, there were 1,741,356 equations: 1,505,938 cow, 229,394 herd-year-season, 6000 sire, and 24 genetic group equations. All known genetic relationships among animals were considered. Genetic group coeffi...

The objectives of this study were to analyze calf performance traits and sex ratio frequencies in reciprocal Bos indicus–Bos taurus F2 Nellore–Angus calves (n = 539). produced using Angus-sired (AN) Nellore-sired (NA) F1 sires dams, resulting four cross types. Calf weight analyzed mixed models. Deviations from 50% ratios tested against expected binomial thresholds. Dam type influenced Julian bi...

The genetic improvement of the Holstein breed in Brazil is supported by use reproductive biotechnologies, mainly due to artificial insemination. Dependent on imported cryopreserved semen, therefore, material from breeders evaluated different environments, this way, Brazilian herds seems be likely not present satisfactory advances, caused phenomenon genotype-environment interaction. Therefore, r...

The objective of this study was, by means of simulation, to quantify the effect of ignoring individual heterogeneity in Weibull sire frailty models on parameter estimates and to address the consequences for genetic inferences. Three simulation studies were evaluated, which included 3 levels of individual heterogeneity combined with 4 levels of censoring (0, 25, 50, or 75%). Data were simulated ...

Milk yield from 273 Angus- and Hereford-sired cows and preweaning performance of their calves were used to determine how accurately milk EPD of Angus and Hereford sires predicted milk production of crossbred daughters and subsequent calf performance. Mean milk EPD (kg) for high Angus (HA), low Angus (LA), high Hereford (HH), and low Hereford (LH) bulls (n = 41) selected as sires were +8.7, -6.2...

A derivation is given for the method proposed by Henderson to incorporate evaluations of sires based on daughter records in other herds into the intraherd prediction of breeding values. The derivation consists of pretending the daughters in other herds have records which have been adjusted for the herd-year-season effects of their origin. These equations then are absorbed into the equation for ...

Animals bred in pastoral systems are often part of multiple-sire groups, introducing uncertainty into pedigrees. Genetic evaluation of sires and dams in such instances is complicated by the uncertainty of parenthood. This article defines a simple and rapid algorithm to compute the inverse of a numerator relationship matrix under uncertain parenthood. The algorithm can accommodate inbreeding and...