Records from 106,212 Nellore animals, born between 1998 and 2006, were

Records from 106,212 Nellore animals, born between 1998 and 2006, were used to estimate (co)variance components and genetic parameters for birth weight (BW), average weight gains from birth to weaning (GBW), average weight gains from weaning to after yearling (GWAY), weaning hip height (WHH), postweaning hip height (PHH) and scrotal circumferences at 9 (SC9), 12 (SC12) and 15 (SC15) months of age. average weight gains will also increase stature. Genetic correlations between BW and average weight gains with scrotal circumferences were all positive and moderate (0.15 0.03 to 0.38 0.01). On the other hand, positive and low genetic associations were estimated between hip height and scrotal circumference at different ages (0.09 0.01 to 0.17 0.02). The results of this study pointed out that selection to larger scrotal circumferences in males will promote changes in average weight gains. In order to obtain Nellore cattle with the stature and size suitable for the production system, both weight gain and hip height should be included in a selection index. (1988), multi-trait evaluation involving both hip height and weight may KL-1 be a better option in size selection. However, in the case of Nellore cattle, nothing regarding genetic correlations between weight gains and hip height has been encountered in the literature. In this sense, there is the need to examine to what extent weight gain, hip height and scrotal circumference respond to selection at different ages, as well as the magnitude of their genetic correlations. With these results at hand, it would be possible to predict changes in hip height of Nellore cattle by correlated response to those traits that are currently being considered in selection programs. Furthermore, this type of work will contribute to the decision to include hip height in Nellore cattle genetic evaluation. This study was conducted with the objective to estimate genetic and phenotypic HIF-C2 manufacture parameters for birth weight, weight gains from birth to weaning, weight gains from weaning to yearling, weaning hip height, postweaning hip height and scrotal circumference at 9, 12 and 15 months of age in Nellore cattle. Material and Methods Data Data were collected from 106,212 Nellore animals, born between 1998 and 2006, all belonging to the Jacarezinho cattle-farm, located in Valparaso County, S?o Paulo State. The main objectives HIF-C2 manufacture of Agropecuria Jacarezinho Ltda. are the sale of young bulls and, heifers and animals for slaughter. In the genetic breeding program developed on the farm, reproductive, growth and finishing traits are used as selection criteria. The animals are weighed at birth, weaning (around 205 days) and as yearlings (around 550 days). In addition, scrotal circumferences are measured at the widest diameter of the scrotum, these measurements being obtained in males from 6 to 22 months of age, at regular intervals of approximately 2 months. Hip height, expressed in centimeters (cm), was measured with a height measuring stick midway-between the hipbones, at a point between the last lumbar and the first sacral vertebrae, immediately before the sacral bone, and thereon to the floor. Hip-height measurement only began to be applied from the year 2003 on. The animals were selected based on empirical indexes, comprising those traits which were being evaluated during the two periods, = vector of observations; = vector of fixed effects; = vector of direct additive genetic effects; = vector of maternal additive genetic effects; p = vector of maternal permanent environmental effects, and = vector of residual random errors associated with observations. and to = genetic (co)variance effects, = relationship matrix; = maternal permanent environmental (co)variance matrix, = identity matrix, = number of dams of animals with records, = number of animals with records, = residual (co)variance matrix, ? direct product between matrices. For the G matrix: and = matrices of direct additive genetic and maternal effects, respectively. Only for BW, GBW and WHH random maternal genetic and maternal permanent environment effects added to the model. For all traits, the fixed effects of contemporary groups, and the age of cows at calving (linear and quadratic effects) were included in the model as covariables. For WHH, PHH, SC9, SC12 and SC15, the animals age at measurement (linear and quadratic effects) was also considered as a covariable. For both GBW and GWAY, the numbers HIF-C2 manufacture of days from birth to weaning and from weaning to after yearling, respectively, were also included as covariables (linear effect). HIF-C2 manufacture A pedigree structure containing the identification of the animals sire and dam was used, with the relationship matrix comprising a total of 153,600 animals. Results and Discussion The means observed, respective standard deviations, coefficients of variation and total numbers of observations for traits studied are.

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