-The effects of weaning age (90 days or 156 days) of female beef calves were evaluated on their subsequent performance from the beginning of the first pregnancy and the end of the second breeding season, at 22/24 months of age. During pregnancy, heifers were managed as a single group on Brachiaria brizantha cv. Marandu pasture; after calving, on bristle oats (Avena strigosa Schreb) and ryegrass (Lolium multiflorum Lam.); and on Brachiaria humidicula pasture during the second reproductive period. The characteristics studied were not influenced by calf weaning age. Heifers submitted to early or conventional weaning weighed 354.5 and 351.9 kg in the post-calving, and 363.4 and 359.2 kg when they weaned their calves. Average daily gain during the breeding season was 0.562 kg, and body condition score was 3.10 and 3.93 at the beginning and end of the experiment, respectively. Average calf birth and weaning weights were not influenced by dam weaning age, and were 28.7 ± 0.74; 86.5 ± 3.26 and 27.4 ± 0.92; 90.3 ± 4.04 kg, respectively, for dams submitted to early or conventional weaning. Dystocia, calving, birth, and weaning rates were not different between weaning ages, with mean values of 29.5; 95.3; 77.3 e 73.4%. Conception rates were 47.9% in the initial third and 40.8% in the second third versus 11.3% in the final third of the breeding season. Heifer average age at conception was 438 and 434 days for early weaning and conventional weaning.Pregnancy rates and production efficiency estimates at calving and calf weaning were not affected by heifer weaning age. Heifer early weaning did not affect their subsequent performance until the end of the second breeding season, at 22/24 months of age.Key Words: body condition, early weaning, heifers, pregnancy rate, weaning age, weight gain Influência da idade de desmame na eficiência reprodutiva de vacas primíparas RESUMO -Avaliaram-se os efeitos da idade de desmame (aos 90 dias e aos 156 dias) de bezerras de corte sobre o seu desempenho subsequente entre o início da primeira gestação e o final do segundo período reprodutivo, aos 22/24 meses de idade.Durante a gestação, as novilhas foram manejadas em grupo único em pastagem de Brachiaria brizantha cv. Marandu; após o parto, em pastagem de aveia (Avena strigosa Schreb) e azevém (Lolium multiflorum Lam.); e, no segundo período reprodutivo, em pastagem de Brachiaria humidicula. As características estudadas não foram influenciadas pela idade de desmame das bezerras. Os pesos vivos pós-parto foram de 354,5 e 351,9 kg e, ao desmame de seus bezerros, 363,4 e 359,2 kg para as bezerras submetidas aos desmames precoce e convencional. O ganho de peso médio diário no período reprodutivo foi 0,562 kg e o escore de condição corporal, de 3,10 no início e 3,93 no final do experimento. Os pesos médios dos bezerros no nascimento e no desmame não foram influenciados pela idade de desmame das mães, com valores de 28,7 ± 0,74; 86,5 ± 3,26 e 27,4 ± 0,92; 90,3 ± 4,04 kg, respectivamente, para as mães submetidas aos desmames precoce e con...