DESEMPENHO E RESPOSTAS ADAPTATIVAS DE NOVILHOS ANGUS X NELORE EM CLIMA TROPICAL

Abstract

The aim of this study was to evaluate the performance and the adaptive profile of de 25 steers ¶ Angus x μ Nelore (RED) and 25 steers ´ Angus x ´ Nelore (NEL), during the milking and the fattening phas-es, in an intensive system, at Rio Grande do Norte state. The body weights, anterior and posterior high, as well as the thoracic perimeter, were monthly measured to evaluate the growth pattern. As adaptive responses were registered rectal temperature and hair coat traits. The statistical analyzes were based in the minimum square method, utilized mixed models. At the beginning of the trial both of genetic groups presented the same body weight (103,03kg) and from the second sampling on the animals RED were superior in comparison with the NEL and showed higher body weight at the weaning (181,60kg RED e 158,57kg NEL) and the 13th months. On the other hand, there was no difference between the genetic groups for the final weight (slaughter body weight). There were differences in all the performance characteristics analyzed. The RED group was superior in relation to the NEL group. The hair coat characteristics didn't differ between the genetic groups, except the hair coat length, which was higher in the RED animals. We concluded that both of genetic groups were adapted to tropical weather conditions, nevertheless, despite the better performance showed by the animals RED during the suckling and the fattening phases, the NEL animal may be indicated because of the similar slaughter body weight.