Heterogeneity of variance and genetic parameters for milk production in cattle, using Bayesian inference.

The goal of this study was to verify the effect of heterogeneity of variance (HV) on milk production in up to 305 days of lactation (L305) of daughters of Girolando, Gir and Holstein sires, as well as in the genetic evaluation of these sires and their progenies. in Brazil. The model included contemporary groups (consisting of herd, year and calving season) as a fixed effect, cow age at calving (linear and quadratic effects) and heterozygosity (linear effect) as covariates, in addition to the random effects of direct additive genetic and environmental, permanent and residual.

Mixed Models in Nonlinear Regression for Description of the Growth of Nelore Cattle.

Body weight records were used to characterize the growth curve of Nelore cattle. Body weight was regressed as a function of age, for both sexes, by using nonlinear models through the functions of Brody, Gompertz, Logistic, Richards, Meloun 1, Von Bertalanffy, and Von Bertalanffy. The quality of the model arrangements was evaluated by employing Akaike and Bayesian Schwarz information criteria.

Polymorphism of the leptin gene in buffalo breed groups from eastern Amazon.

The objective of this work was to characterize genetically some buffalo herds raised in Varzea (VA) and Terra-Firme (upland) (TF) ecosystems through polymorphism of the intron 2 of the leptin gene ( LEP-1620). Two hundred seventy-nine animals from four distinct populations were evaluated using the PCR-RFLP method for LEP-1620 polymorphism (SNP) of the leptin gene with restriction enzyme BsaAI. The animal samples were sorted into 4 groups, according to their breed and environmental origin: Mediterranean TF, Murrah TF, Mediterranean VA and Crossbreed VA.

Association of polymorphisms of the β-defensin 1 gene with nematode and protozoan infection traits in goat.

This study's purpose was to identify polymorphisms (SNP) in the goat β-defensin 1 gene and to associate these SNPs with traits related to nematodean and protozoan infections in Anglo-Nubian goats from semiarid region of Brazil. A total of 184 animals were used for DNA extraction, PCR and DNA automatic sequencing. The association analyses included the fixed effects of animal age, bloodline and genotype of the SNP marker in the statistical model.

Karyotypic evolution of ribosomal sites in buffalo subspecies and their crossbreed.

DOMESTIC BUFFALOES ARE DIVIDED INTO TWO GROUP BASED ON CYTOGENETIC CHARACTERISTICS AND HABITATS: the "river buffaloes" with 2n = 50 and the "swamp buffaloes", 2n = 48. Nevertheless, their hybrids are viable, fertile and identified by a 2n = 49. In order to have a better characterization of these different cytotypes of buffaloes, and considering that NOR-bearing chromosomes are involved in the rearrangements responsible for the karyotypic differences, we applied silver staining (Ag-NOR) and performed fluorescent in situ hybridization (FISH) experiments using 18S rDNA as probe.