Related GMR Articles
For genetic evaluation of beef cattle, univariate or bivariate analyses are often performed as an alternative to decrease the complexity of matrices and mathematical models compared to multivariate analysis, which considers a larger number of joint traits. The use of bivariate methods to calculate genetic predictors may cause bias in the estimation of breeding values and, as a ... more
The continuous trait age at subsequent rebreeding (ASR) was evaluated using survival analysis in Nellore breed cows that conceived for the first time at approximately 14 months of age. This methodology was chosen because the restricted breeding season produces censored data. The dataset contained 2885 records of ASR (in days). Records of females that did not produce calves in the ... more
The objective of this study was to quantify the magnitude of genotype-environment interaction (GxE) effects on age at first calving (AFC), scrotal circumference (SC), and yearling weight (YW) in Nellore cattle using reaction norms. For the study, 89,152 weight records of female and male Nellore animals obtained at yearling age were used. Genetic parameters were estimated with a single- ... more
Weight gain is a key performance trait for beef cattle; however, attention should be given to the production costs for better profitability. Therefore, a feed efficiency trait based on performance can be an interesting approach to improve performance without increasing food costs. To identify candidate genes and genomic regions associated with residual body weight gain (RWG), we ... more
Beef cattle production requires reproductive efficiency. However, measures of reproductive traits are not usually collected; consequently, correlated traits that could be used as indicators would be useful. We examined associations between measures of reproductive and productive efficiency that could be used as selection indicators. Data from 194 dams of the genetic groups Angus x Nelore ... more
The aim of the present study was to identify polymorphisms in the leptin gene of 112 pigs and compare the maternal and paternal lineage of Pietrain and Large White breeds that underwent a divergent selection for over 30 years. DNA samples extracted from the blood of these animals were amplified by polymerase chain reaction and genotyped by restriction fragment length polymorphism ... more
Leptin is expressed in various tissues, suggesting that this protein is effective not only at the central nervous system level, but also peripherically. Recent studies have shown leptin production by other tissues, including the placenta, stomach, and mammary tissues, but there is no information available concerning expression levels of leptin in the rat mammary gland at different activation ... more
Mutations in the melanocortin-4 receptor (MC4R) are associated with severe obesity, independent of their effect on cortisol or thyroid-stimulating hormone levels. We examined a morbidly obese male (BMI = 62 kg/m2) with a binge-eating disorder and eight family members for mutations in the MC4R gene and potential differences in leptin levels. Fifty healthy individuals served as ... more
The aim of this study was to investigate the relationship between the leptin receptor (LEPR) polymorphism/serum leptin level and preeclampsia. The prevalence of a single nucleotide polymorphism in the LEPR gene exon 14 at -656 and the serum leptin concentrations in 97 preeclamptic pregnant mothers were compared to those of 110 healthy controls. The Lys656Asn genotype and ... more
Leptin is an important regulator of appetite, energy metabolism, and reproduction and is mainly synthesized in the adipocytes and then secreted into the bloodstream. The leptin receptor was classified as type I cytokine receptor due to its structural homology with IL-6 receptors and the signaling pathways in which they are both involved. The aim of our study is to comparatively assess the ... more