Evaluation of F1 calves sired by Brahman, Boran, and Tuli bulls for birth, growth, size, and carcass characteristics.

Birth (n = 308), weaning (n = 291), feedlot and carcass (n = 142), and yearling heifer traits (n = 139) were evaluated in F1 calves sired by Brahman (BR), Boran (BO), and Tuli (TU) bulls and born to multiparous Hereford and Angus cows. Calves sired by BR were heaviest (P < .05) at birth and largest (P < .05) for cannon bone length. Tuli crosses were smaller (P < .05) for birth weight and cannon bone length than BR and BO crosses. No significant differences were observed for gestation length among sire breeds. Brahman crosses had larger (P < .05) weaning weight, hip height, and preweaning ADG than calves sired by BO and TU. Similar trends were observed for feedlot traits. Carcasses of BR crosses were heavier (P < .05) and had less (P < .05) internal fat than those of BO and TU crosses. Tuli crosses averaged greater (P < .05) skeletal maturity than BO crosses. Tuli crosses averaged greater marbling (P < .05) than BR crosses and less (P < .05) Warner-Bratzler shear force than BO crosses. No differences were observed in longissimus muscle area, fat thickness, or yield grade among sire breeds. Heifers sired by BR were heaviest (P < .05) and tallest (P < .05) at yearling measurement. Brahman F1 heifers had larger (P < .05) pelvic height and pelvic area, due to larger skeletal frame size, than BO and TU F1 heifers. These results indicate large differences in growth and skeletal size exist among calves sired by these three breeds. Several important differences also exist for carcass quality traits, but not for carcass yield traits, among these three breeds.