Productivity and production efficiency of cows of different genetic groups submitted to cultivated pastures during pre or postpartum

We assessed through the weight of cows and calves up to weaning at 90 days and the reproductive performance from pregnancy to weaning, the productivity and efficiency of 94 Charolais (CH), Nellore (NE), ½CH ½NE e ½NE ½CH cows submitted the following feeding systems: cows kept on native pasture (NP); cows kept on cultivated pasture (CP), composed of oat (Avena sativa), ryegrass (Lollium multiflorum) and clover (Trifolium vesiculosum) from July 15 to September 15 and the remainder of the trial on natural pasture (CPN); and cows kept on cultivated pasture during September 15 to November 15, and the remainder on native pasture (NPC). Cows kept on CP produced 22.6% more calves than cows kept exclusively on NP, and were more efficient (P