Hip height and its relationships with reproductive and growth traits in Nelore cattle

Abstract

The objective of this work was to determine factors that affect hip height at different ages, in Nelore cattle, and to estimate the heritability and the genetic correlation between this character and reproductive and growth traits. The analyzed traits were: hip height at weaning, hip height at post weaning, weight at weaning, weight at post weaning, scrotal circumference, and age at first calving. The analyzed factors were: year and month of birth, herd, sex, age of dam at calving, and calf age. The variance covariance components were estimate by the restrict maximum likelihood methodology using animal model. All effects were significant for hip height at different ages. The heritability estimates for direct genetic effects indicated that the growth and reproductive traits respond to selection, except for age at first calving. The genetic correlations between growth traits were positive and high, from 0.42 to 0.90, which indicates that they are mostly determined by the same group of genes with additive action. Due to the low magnitude of the estimated genetic correlations, from -0.14 to 0.16, the reproductive efficiency is little influenced by selection for hip height.