U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


Date of this Version


Document Type



The Professional Animal Scientist 20 (2004):330–335


Calving difficulty, survival from birth to weaning, birth weight, and weaning weight of 167 calves and carcass traits of 88 cattle (63 for adjusted fat thickness) were compared for progeny of Red Poll and Longhorn bulls mated to crossbred cows that calved at 2 or 3 yr of age. Results indicated that Longhornsired calves required 28% less assistance at calving than Red Poll-sired calves when dams calved at 2 yr of age (P<0.05), but there was no difference between Red Poll- and Longhorn-sired calves for calving difficulty with 3- yr-old cows. Red Poll-sired calves had significantly greater birth and weaning BW than did Longhorn-sired calves for 2-yrold dams. Significant differences attributable to sire breed were found only for bone percentage of progeny of 3-yr-old dams, but not for carcass weight, fat thickness, longissimus area, USDA quality grades, and percentages retail product, fat trim, or bone. There was a significant interaction between sire breed and age of dam only for calving difficulty. Within sire breed, calving difficulty of 2- yr-old dams was greater than that for 3- yr-old dams, and calves from 2-yr-old dams also were significantly lighter at weaning than were calves from 3-yr-old dams (P<0 .01).