Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2007
Publication Date: 11/2/2007
Publication URL: http://jas.fass.org/cgi/reprint/85/11/2904
Citation: Casas, E., Lunstra, D.D., Cundiff, L.V., Ford, J.J. 2007. Growth and pubertal development of F1 bulls from Hereford, Angus, Norwegian Red, Swedish Red and White, Friesian, and Wagyu sires. Journal of Animal Science. 85:2904-2909. Interpretive Summary: The Germplasm Evaluation Program at USMARC in the past has and currently continues to evaluate numerous breeds of cattle that are used in beef production in the United States. The current study characterized male reproductive traits in bulls produced from sires of British, Scandinavian, and Japanese breeds. Bulls with Swedish Red and White or Japanese Wagyu inheritance reached puberty at an older age relative to Angus-sired bulls. Wagyu-sired bulls also had the slowest growth rate. These observations will aid producers who assess Swedish Red and White- or Japanese Wagyu-sired bulls for their rate of pubertal development. Likewise, the similarities of other reproductive traits among crossbred bulls of the other breeds investigated have the potential to impact producers who use them. These findings will also be of value to investigators in future experimental design.
Technical Abstract: The objective of the study was to characterize body growth, testicular development and puberty between 8 and 14 mo of age in bulls (n = 120) produced by mating sires from Hereford, Angus, Norwegian Red, Swedish Red and White, Friesian, and Wagyu, to MARC III (1/4 Hereford, 1/4 Angus, 1/4 Red Poll, 1/4 Pinzgauer) cows. Traits evaluated were birth weight, weight at 200 d, weaning weight (at 215 d), yearling weight, ADG from 8 to 14 mo of age, paired testis volume growth from 8 to 14 mo of age, age at puberty (determined by production of 50 x 10**6 sperm with 10% motility), age at freezable semen (determined by production of 500 x 10**6 sperm with 50% motility), and at 15 mo of age, paired testis weight and daily sperm production per testis pair. Differences in weight were observed (P = 0.04) at birth; bulls with Hereford and Friesian were heavier at birth (43 kg and 41 kg, respectively), when compared to those with Norwegian Red, Swedish Red and White, and Wagyu inheritance (39 kg, 38 kg, and 38 kg, respectively). Differences in weight were also observed at one year of age (P = 0.004), where the heaviest animals were those sired by Angus (450 kg), while the lightest animals were those sired by Wagyu (403 kg). Bulls with Wagyu inheritance had the lowest (P = 0.0003) ADG (1.13 kg/d) when compared to bulls with inheritance from Hereford (1.23 kg/d), Angus (1.29 kg/d), Norwegian Red (1.27 kg/d), Swedish Red and White (1.24 kg/d), and Friesian (1.27 kg/d). Differences in scrotal growth rate were not significant (P > 0.10). They ranged from 1.95 in Angus sired to 1.66 cm**3/d in Wagyu sired bulls. There was a tendency (P = 0.06) of sire breed for age at puberty; puberty for animals with Hereford, Angus, Norwegian Red, Swedish Red and White, Friesian, and Wagyu inheritance was 272 d, 268 d, 272 d, 301 d, 277 d, and 302 d, respectively. There were no differences (P = 0.80) for age at freezable semen (335 +/ 10 d). At slaughter (15 mo of age), there were no differences (P > 0.05) for paired testis weight (603 +/ 28 g) and daily sperm production (10.6 x 10**9 +/ 0.9 x 10**9 per testis pair). Growth of bulls with Wagyu inheritance was slower than animals with dairy breed inheritance (Norwegian Red, Swedish Red and White, and Friesian) and beef breed inheritance (Hereford and Angus). At 15 mo of age testicular development was similar for all breeds despite differences in mature body weight.