Genetic parameters and environmental effects were estimated for 9,355 Nelore cattle scrotal circumference measurements (PE). The univariate analysis considered animal effect (random effect) and fixed effects of contemporary group (GC) and linear and quadratic effects of age at yearling (IDS) and yearling weight adjusted to 550 days (PSAJ). Contemporary group was defined by: year, season at birth and management group at birth, weaning and yearling. Heritability estimates were: 0.42 ± 0.04 (after IDS and PSAJ); 0.41 ± 0.04 (after PSAJ) and 0.35 ± 0.03 (adjusting only for IDS).
beef cattle; heritability; sexual precocity
