Comparison of F-1 Bos indicus x Hereford cows in central Texas: I. Reproductive, maternal, and size traits

Cows (n = 116) sired by Angus, Gray Brahman, Gir, Indu-Brazil, Nellore, and Red Brahman bulls and from Hereford dams were evaluated (when bred to the same breed of bull) for reproductive performance and cow weight and height and their calves (n = 1,161) were evaluated for birth and weaning weight in central Texas (temperate winters and subtropical summers). Cows were born from 1982 to 1985 and their calves were born from 1985 to 1999. Crossbred c ows sired by Angus had a higher (P < 0.10) occurrence of calving difficulty than Gir, Indu-Brazil, Nellore, and Red Brahman crossbred. Calves from Gir crossbreds had lighter (P < 0.10) birth weight (34.8 kg) than calves from Angus and Red Brahman crossbreds (39.4 and 37.2 kg). Calves from Angus cros sbreds cows had lighter (P < 0.001) weaning weight (227.0 kg) than calves f rom Bos indicus crossbreds. Cows sired by Angus were lighter (P < 0.10) as mature cows (520.69 kg) than Gray Brahman, Indu-Brazil, and Red Brahman cro ssbreds (585.6, 571.9, and 577.6 kg, respectively). They also had smaller ( P < 0.05) hip height (124.7 cm) than Bos indicus crossbreds. Mature cows si red by Indu-Brazil had greater (P < 0.05) hip height (138.3 cm) than Gir cr ossbreds (133.8 cm). Differences among sire breeds were noted within cow ag e categories (2 through 14 yr of age) for pregnancy rate, calf crop born, c alf survival rate las a trait of cow), and calf crop weaned. Angus and Indu -Brazil crossbred cows were lower (P less than or equal to 0.10) than Gir a nd Nellore crossbreds for pregnancy rate, calf crop born, and(or) calf crop weaned at some, but not all, ages. Indu-Brazil crossbreds had a lower (P l ess than or equal to 0.10) calf survival rate than most other breed groups at ages 11 to 14 yr. The results of this study indicate that Nellore and Gi r crossbreds, but not Indu-Brazil, could perform as well or better than bre eds traditionally used in crossbreeding programs of U.S. cow-calf productio n.