Evaluation of Zebu breeds for beef production based on birth, growth, and carcass characteristics

Typescript (photocopy).Birth, growth and carcass data on cattle raised at Riesel, Texas were analyzed to evaluate Zebu sire breed differences. Zebu breeds included Gray Brahman (B), Red Brahman (R), Gir (G), Indu-Brazil (I) and Nellore (N). Angus (A) was used as a control. Calves were produced by AI matings with Hereford cows obtained from 15 sources and having had at least one calf. Breed of sire was the major effect of concern in all statistical analyses. Birth year and sire nested within breed (random effect) were included in all models. There were no significant differences among sire breeds for calving ease or calf vigor scores. Zebu crosses had longer gestations (P<.05), heavier birth weights, longer cannon bones (P<.05) and greater heart girths than A crosses. Nellore crosses had the longest gestations and I crosses were heaviest and largest at birth while G crosses had the shortest gestations and were lightest and smallest of the Zebu crosses. There were no significant breed differences for preweaning gain or weaning weight, but A crosses were smaller than Zebu for weaning height (P<.05). Indu-Brazil and N crosses were tallest and G were shortest of the Zebu crosses. Angus crosses had the lowest postweaning gain (P<.05); all Zebu crosses were similar. Yearling weights of A crosses were lighter than the Zebu crosses; R and B were heaviest and I, N and G were lightest of the Zebu crosses. The Zebu crosses were also taller than A as yearlings (P<.05); N, I and R crosses were taller than B and G. Angus crosses were shorter at initial and final feedlot heights; N, I and R crosses were taller than G and B at both times. Angus crosses were similar to G and N for final feedlot weight and lighter than R, I and B, but A, R, I and B were higher than G and N for average daily gain. Breed was significant for heifer weights and heights at 12, 18 and 24 mo. Angus crosses were smallest, among Zebu crosses, B and R were heaviest and I, N and G were similar and lighter. Indu-Brazil crosses were tallest, G shortest and N, B and R intermediate. Angus crosses had more desirable (P<.05) marbling scores and USDA quality grades than did the Zebu crosses which were similar. There were no other significant breed differences among Zebu crosses for carcass quality or yield characteristics. These results indicate that among these Zebu breeds large differences exist for birth and growth measurements while somewhat smaller differences exist among them for carcass characteristics