Comparison of Longhorn- and Red Poll-Sired Calves from Crossbred Dams Calving at Two or Three Years of Age

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 Polland Longhorn-sired calves for calving difficulty with 3yr-old cows. Red Poll-sired calves had significantly greater birth and weaning BW than did Longhorn-sired calves for 2-yrold dams. Significant differences attribut1Published as Journal Series no.13795, Nebraska Agric. Res. Div., Univ. of Nebraska, Lincoln 68583-0908. 2Current address: College of Animal Science and Technology, Yunnan Agricultural University, Kunming City, Yunnan Province, People’s Republic of China. 3To whom correspondence should be addressed: [email protected] able 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 2yr-old dams was greater than that for 3yr-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). (