Growth performance and carcass characteristics of Nelore Angus and Nelore Angus Guzera crossbreed cows fed with supplemented pasture during the yearling and feedlot stages

Abstract

The objective of this study was to evaluate the growth performance of two crossbreed genetic groups, ½ Nelore ½ Angus and ¼ Nelore ¼ Angus ½ Guzera, which originate from the rotational crosses of Nellore cows with Angus bulls and ½ Nellore ½ Angus cows with Guzera bulls, respectively. The growth performance was evaluated at the end of the yearling and feedlot stages, and carcass characteristics were evaluated after the slaughter. A completely randomized trial design was used, with 12 cows in each group. The yearling stage lasted 270 days, and the cattle were fed with pasture of Brachiaria brizantha 'Marandu' with 2.0 UA ha-1 and a forage allowance of 2.5 kg of dry matter (DM) per 100 kg of live weight (LW), during this stage the animals, with an average age of 365 ± 10 days, received protein and energy supplementation ad libitum. After the yearling stage, the cows were confined until they reached the age of 22-24 months and received 6.0 kg DM of sugar cane + urea and 4.0 kg DM of concentrate, with 150 g kg-1 of crude protein (CP), daily during 90 days. The daily average weight gain (DAWG) during the yearling stage was higher for the ½ Nelore ½ Angus group. The ¼ Nelore ¼ Angus ½ Guzera group reached higher slaughter weight because they had higher DAWG during the feedlot stage (1.022 vs. 728 g dia-1). No significant difference (P > 0.05) was found between the groups when the hot carcass weights were compared. The ½ Nelore ½ Angus group reached a higher carcass weight percentage (53 vs. 50 %) and subcutaneous fat thickness (4.3 vs. 4.0 mm).