Beef X beef and dairy X beef females mated to Angus and Charolais sires II. Calf growth, weaning rate and cow productivity.

Abstract

Preweaning growth of 814 progeny was studied, and weaning rate and kilograms of calf weaned/cow exposed were determined for 310, 2- to 7-yr-old angus x Hereford (AH), Charolais X Hereford (CH), straight bred Hereford (HH) and Brown Swiss X Hereford (SH) cows mated to Angus and Charolais bulls. Charolais-sired calves grew more rapidly (P less than .01) then Angussired calves were heavier (P less than .01) at 130 and 210 d of age. Progeny of SH females grew faster (P less than .05) and were the heaviest at 130 (164 kg) and 210 (231 kg) d, whereas calves from HH dams grew the slowest and weighed the least (P less than 0.5) at 130 (125 kg) and 210 (180 kg) d of age. Progeny from AH and CH dams had similar 130-d weights (CW130) and made similar daily gains from birth to 130 of age (ADGI). Calves from CH females gained faster (P less than .05) from 130 to 210 d (ADG2) and had higher (P less than .05) 210-d weights (CW210) than did calves from AH dams. ADG1 and ADG2 of male calves were .043 and .072 kg/d greater, respectively (P less than .01) than those of heifer calves. Age of dam influenced (P less than .01) calf preweaning gains and weights. Calves from 4- to 7-yr old cows had greater (P less than .05) ADG1 and ADG2 and higher (P less than .05) CW130 and CW210 than progeny of younger dams. Progeny of 2-yr-old cows grew more slowly (P less than .05), and were last (P less than .05) in all traits (ADG1, ADG2, CW130 and CW210), whereas progeny of 3-yr-old cows were intermediate to those of 2 and 4- to 7-yr-old females. Cow breed type influenced (P less than .01) weaning rate (WR) and kilograms of calf weaned/cow exposed. SH females has the highest WR (83.4%), AH and CH were intermediate at 76 .8 and 77.7%, respectively, and HH dams had the lowest (P less than .05) WR, 66.4 calves/100 cows exposed. SH cows weaned 34.6 kg more (P less than .05) calf/cow exposed than AH and CH dams. HH dams were least productive (P less than .05), weaning 122.3 kg calf/cow exposed. Dairy X beef dams (SH) weaned 47.6 kg more (P less than .01) calf/cow exposed than the average of beef X beef dams (AH, CH, HH). Dairy X beef females had the highest WR and weaned the heaviest calves.