Desempenho e características de carcaça de bovinos de corte de quatro grupos genéticos terminados em confinamento

Abstract

The objective of this work was to evaluate feedlot performance of Tabapuã (T) and Bonsmara (B) purebreed animals, and 1/2 Bonsmara + 1/2 Nelore (B1) and 1/2 Bonsmara + 1/2 Red Angus + 1/2 Nelore (B2) crossbred animals. It was used five castrated bovines from each genetic group at average age of 22 months and live weight of 394 ± 21 kg at the beginning of the experiment. The diet for all the animals contained sugar cane silage and commercial ration at the proportion of 55 and 45% (dry matter basis), respectively, with 14.99% CP and 59.84% TDN. Animals were slaughtered when they reached a visual finishing body score of 3, in a scale from 1 = thin to 5 = obese. There was a significant effect of genetic groups on dry matter intake, whose averages were 1.9, 2.1, 2.2 and 2.2% BW for Tabapuã, Bonsmara, B1 and B2 animals, respectively. Average daily gain in live weight of crossbred animals B1 (0.925 kg) and B2 (1.122 kg) and purebred Bonsmara (1.035 kg) were greater than the ones of Tabapuã (0.630 kg), which were the latest to reach body condition score for slaughtering. Nutrient intake, as percentage of the body weight or per unit of metabolic weight, did not differ among genetic groups. Carcasses of Bonsmara animals presented the best conformation score, but carcasses of Tabapuã animals obtained the best means for hot (56.2%) and for cold (55.2%) dressing percentages. There was no difference for cold carcass weight among the genetic groups. Purebred Bonsmara steers, B1 and B2, presented better fedlot performances in comparison to Tabapuã steers. © 2011 Sociedade Brasileira de Zootecnia.