Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/2/2010
Publication Date: 4/2/2011
Citation: Casas, E., Thallman, R.M., Cundiff, L.V. 2011. Birth and weaning traits in crossbred cattle from Hereford, Angus, Brahman, Boran, Tuli, and Belgian Blue sires. Journal of Animal Science. 89:979-987. Interpretive Summary: The beef industry is under pressure to increase beef production. The objective of this project was to evaluate birth and weaning traits in offspring from heavily muscled breeds, to be used by U.S. producers. Differences were assessed in crossbred offspring produced by mating Hereford, Angus, Brahman, Boran, Tuli, and Belgian Blue sires to Hereford, Angus, and MARC III cows. Under temperate conditions, offspring from Brahman sires grew faster and were heavier at birth and at weaning; however, Brahman sires produced offspring that required more assistance at calving and had the lowest survival rate. Progeny from Boran and Tuli sires had similar difficulty at calving than progeny from Hereford and Angus calves, but were the lightest animals at weaning. Breed differences can be exploited to optimize performance levels in crosses or in composite populations relatively more quickly than performance can be optimized by selection.
Technical Abstract: The objective of this study was to characterize breeds representing diverse biological types for birth and weaning traits in crossbred cattle. Gestation length, calving difficulty, percentage of unassisted calving, percentage of perinatal survival, percentage of survival from birth to weaning, birth weight, weight at 200 d, and ADG, was measured in 2,500 calves born and 2,395 calves weaned. Calves were obtained by mating Hereford, Angus and MARC III (¼ Hereford, ¼ Angus, ¼ Pinzgauer, and ¼ Red Poll) mature cows to Hereford or Angus (British breeds), Brahman, Tuli, Boran, and Belgian Blue sires. Calves were born during the springs of 1992, 1993, and 1994. Sire breed was significant for all traits (P < 0.002). Offspring from British breeds and Belgian Blue had the shortest gestation length (285 d), when compared to progeny from other sire breeds (average of 291 d). Calving difficulty was greater in offspring from Brahman sires (1.24), while the offspring from Tuli sires had the least amount of calving difficulty (1.00). Offspring from all sire breeds had similar perinatal survival and survival from birth to weaning (average of 97.2 and 96.2%, respectively) with the exception of offspring from Brahman sires, which was lower (92.8 and 90.4%, respectively). Progeny of Brahman sires were heaviest at birth (45.7 kg), followed by offspring from British breeds, Boran, and Belgian Blue sires (average of 42.4 kg). The lightest offspring at birth was from Tuli sires (38.6 kg). Progeny derived from Brahman sires were the heaviest at 200 d (246 kg), and grew faster (1.00 kg/d) than any other group. Progeny of British breeds and Belgian Blue had an intermediate weight at 200 d (238 kg), and ADG (average of 0.98 kg/d). Progeny of Boran and Tuli sires were the lightest at 200 d (227 kg), and the lowest ADG (0.93 kg/d). Male calves had a longer gestation length, higher incidence of calving difficulty, higher mortality to weaning, and were heavier and grew faster than female calves. Sire breed effects can be optimized by selection and use of appropriate crossbreeding systems.