POSTWEANING PERFORMANCE AND CARCASS MERIT OF F1 STEERS SIRED BY BRAHMAN AND ALTERNATIVE SUBTROPICALLY ADAPTED BREEDS

Comparisons were made among F-1 steers sired by Brahman and alternativ e subtropically adapted breeds of bulls for feedlot and carcass traits when steers were produced from Augus- and Hereford-type dams. Brahman -derivative breeds included Brangus, Beefmaster, and Santa Gertrudis. Brangus- and Beefmaster-sired steers weighed less at slaughter, wherea s carcasses of Brangus- and Santa Gertrudis-sired steers had more marb ling than those of Brahman-sired steers. Brahman-sired steer carcasses had greater longissimus muscle area than carcasses of Santa Gertrudis -sired steers. Other Zebu breeds compared to Brahman were Boran, Gir, Indu-Brazil, Nellore, Red Brahman, and Sahiwal. Steers by Brahman sire s had higher slaughter weights than steers by Boran, Gir, Nellore, or Sahiwal sires. Hot carcass weights of Brahman-sired steers were also h igher than those of Boran- and Sahiwal-sired steers. Steer carcasses b y Brahman sires had greater longissimus muscle area than those of stee rs by Sahiwal sires. Non-Zebu breeds included Tuli and Senepol. Steers by Tuli sires grew slower, had lower slaughter weights, and their car casses weighed less than those of Brahman-sired steers. Brahman-sired steer carcasses had greater longissimus muscle area but less marbling than carcasses of Tuli-sired steers. These data suggest that steers by Brahman sires have an advantage for slaughter weight over steers by B rangus, Beefmaster, Boran, Gir, Nellore, Sahiwal, and Tuli sires, but their carcasses are at a disadvantage for marbling score compared with those by Brangus, Boran, Nellore, and Tuli sires.