The objective of the experiment was to evaluate the weight, the feed intake, the average weight gain and feed: gain ratio of culled cows, straightbreds (Charolais-C and Nellore-N) and crossbreds (½ CN and ½ NC) during the finishing phase as well as measuring the resulting heterosis. The cows were confined during 80 days, all of them fed with a 10% crude protein diet and forage: concentrate ratio of 65:35. The F1 cows were heavier at the beginning (402 vs. 362 kg) and at the end of the feedlot confinement (524 vs. 475 kg), being the heterosis of 11.05 and 10.31%, respectively. The average weight gain of the F1 cows (1.557 kg) was similar to the straightbreds (1.424 kg). The dry matter intake (DMI) in kg/animal.day (DMID) was 11.26% higher for F1 than for straightbred cows. However, when DMI was expressed in relation to the metabolic weight (DMIM) and per 100 kg of LW (DMIP), the difference decreased to 3,25 and 3,57%, respectively, and became non significant. The C cows were heavier and showed higher average daily gain (1.553 vs. 1.424 kg) than he N. The F1 ½ CN cows were heavier and more efficient in converting feed in weight gain, than the ½ NC.
average weight gain; Bos indicus; Bos taurus; Charolais; feed intake; Nellore
