PREWEANING GROWTH OF ANGUS (BOS-TAURUS), AND BRAHMAN (BOS-INDICUS), AND TULI (SANGA) SIRED CALVES AND REPRODUCTIVE-PERFORMANCE OF THEIR BRAHMAN DAMS

Calves born to Angus (A), Brahman (B), or Tuli (T) bulls and B cows we re evaluated to determine sire breed of calf effects on preweaning cal f growth and reproductive performance of their darns. Records from 242 cow-calf pairs over 2 yr were used to assess birth weight, calf ADG, weaning weight, gestation length, and postpartum interval to estrus (P PI). The sire breed x sex of calf interaction was important (P < .05) for birth weight, weaning weight, and gestation length. Birth weights of BB males (32.8 +/- .8 kg) were significantly heavier than for AB an d TB males (30.1 +/- .9 and 28.6 +/- .7 kg, respectively) and BB femal es (29.4 +/- .7 kg). As a main effect, sire breed of calf affected (P < .05) calf ADG, weaning weight, gestation length, and PPI. Calf ADG a nd weaning weights were greater for AB (.90 +/- .01 kg/d; 220.9 +/- 3. 5 kg) than for TB (.81 +/- .01 kg/d; 200.4 +/- 3.0 kg) and BB calves ( .78 +/- .01 kg/d; 198.8 +/- 3.5 kg). Gestation lengths differed (P < . 01) among all calf genotypes (284, 288, and 294 +/- 1 d for AB, TB, an d BB, respectively). Postpartum intervals were shorter (P < .05) for c ows nursing BB calves (83 +/- 4 d) than for cows nursing AB (95 +/- 5 d) and TB calves (97 +/- 4 d), Tuli-sired F-1 calves were inferior to Angus-sired F-1 calves and similar to straightbred Brahman calves in p reweaning growth. Crossbred calves had shorter gestations but longer p ostpartum intervals than purebred calves.