Average daily gain from weaning (GMD--12) to yearling weight (P12M) of Nellore, Guzerá x Nellore (GN), Red Angus x Nellore (RN), and Marchigiana x Nellore (MN) cattle, from a crossbreeding experiment conducted at the IAPAR Paranavaí Experimental Station, produced by artificial insemination, born between 1985 and 1997 within two annual birth seasons (January - April and July - December), were analyzed. The least squares method was utilized to study 634 observations of GMD_D12 and of P12M. Calf's birth month was a significant effect for GMD_D12 and for P12M. For both traits, there were relevant effects of the factors calf birth year and sex, genetic group or breed, sire within genetic group, and the interaction between the animal sex by genetic group. The least squares means and respective standard errors, always in the sequency N, GN, RN and MN were: 0.247 ± 0.009 kg, 0.287 ± 0.010 kg, 0.366 ± 0.010 kg, and 0.352 ± 0.012 kg, for GMD_D12, and 176.82 ± 1.86 kg, 190.59 ± 2.07 kg, 223.30 ± 2.31 kg, and 214.12 ± 2.31 kg, for P12M.
beef cattle; crossbreeding; post-weaning weight gain; yearling weight
