PSIV-25 Growth of beef x dairy crossbred calves sired by Angus, Charolais, Hereford, Limousin, and Simmental.

Abstract The objective of this study was to compare beef x dairy crossbred calves sired by Angus, Charolais, Hereford, Limousin, and Simmental in an experimental research herd. Sire breed groups were compared for growth during the pre-weaning and growing stage until harvest. Calves were from Holstein dams, and crossbred dams of Montbéliarde, Viking Red, and Holstein, and crossbred dams of Jersey, Normande, and Viking Red. Breed groups were Angus (n = 11), Charolais (n = 11), Hereford (n = 11), Limousin (n = 10) and Simmental (n = 7) crossbred calves. Calves were born from September 2023 to December 2023 at the University of Minnesota West Central Research and Outreach Center in Morris, MN. During the pre-weaned phase, calves were fed 10 L/d, and calves were introduced to the automated feeder at day 5 and were weaned at 63 d. Milk feeding behaviors (drinking speeds) were collected from the automatic feeding system and analyzed by breed groups. Body weights were recorded at birth and weekly through weaning, as well as monthly through harvest. Variables included in the statistical model for analyses were fixed effects of birthweight, sire breed group and dam group. Angus-sired (37.6 kg) calves had lower (P < 0.05) birth weight compared to Limousin (42.3 kg) and Simmental (43.2 kg) calves. Hereford calves (107.5 kg) had the highest weaning weight and was higher (P < 0.05) than Limousin (97.3 kg) and Charolais (96.2 kg) calves. Furthermore, Hereford calves (1.06 kg/d) had higher (P < 0.05) average daily gain compared to Limousin (0.89 kg/d) and Charolais (0.88 kg/d) calves. Angus and Simmental calves had average daily gains of 0.98 kg/d and 0.97 kg/d, respectively. Days to harvest (P < 0.04) was 452 for Angus, 474 for Charolais, 448 for Hereford, 458 for Limousin, and 451 for Simmental calves. Overall, sire breed groups were not different (P < 0.05) for final weight at harvest (646 kg for Angus, 653 kg for Charolais, 651 kg for Hereford, 618 kg for Limousin, and 635 kg for Simmental). The results from this study found that some breeds groups differ in growth rate from birth to harvest; however, the differences were subtle and numerous beef sire breeds may be used to breed dairy cattle.