Submitted to: American Society of Animal Science Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/30/2007
Publication Date: 7/8/2007
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 [abstract]. Journal of Animal Science. 85(Suppl. 1):475. Abstract #W35.
Technical Abstract: The objective of the study was to characterize growth, testicular development and puberty between 9 and 14 mo of age in bulls (n = 120) produced by mating sires from Hereford (H), Angus (A), Norwegian Red (N), Swedish Red and White (S), Friesian (F), and Wagyu (W), to MARC III (¼ Hereford, ¼ Angus, ¼ Red Poll, ¼ Pinzgauer) cows. Traits evaluated were birth weight, weight at 200 d, weaning weight (at 215 d), yearling weight, average daily gain 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 106 sperm with 10% motility), age at freezable semen (determined by production of 500 x 106 sperm with 50% motility), paired testis weight, and daily sperm production per testis pair at 15 mo. At birth; animals with H and F inheritance were heavier (43 kg and 41 kg, respectively, P +0.04), when compared to those with N, S, and W 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 with A inheritance (450 kg), while the lightest animals were those with W inheritance (403 kg). Bulls with W inheritance had the lowest (P = 0.0003) average daily gain (1.13 kg/d) when compared to bulls with inheritance from H (1.23 kg/d), A (1.29 kg/d), N (1.27 kg/d), S (1.24 kg/d), and F (1.27 kg/d). No differences (P = 0.14) were observed for paired testis volume growth rate. They ranged from 1.95 in A sired to 1.66 cm3/d in W sired bulls. There was a tendency (P = 0.06) of sire breed for age at puberty. The range was from 268 to 302 d. There were no differences (P > 0.05) for paired testis weight and daily sperm production. Growth of animals with W inheritance is slower than animals with N, S, F, H, or A inheritance. At 15 mo of age testicular development was similar for all breeds despite predicted differences in mature body weight.