|Wang, Xiang Zu - GANSU AGRICUL. UNIVERSITY|
|Gao, Feng Qin - GANSU AGRICUL. UNIVERSITY|
|Wu, Jian Ping - GANSU AGRICUL. UNIVERSITY|
|Lalman, D - GANSU AGRICUL. UNIVERSITY|
Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: December 16, 2007
Publication Date: February 2, 2008
Citation: Brown, M.A., Wang, X., Gao, F., Wu, J., Lalman, D.L. 2008. Postweaning gains in calves sired by six sire breeds evaluated under two postweaning management systems [abstract]. American Society of Animal Science Southern Section Meeting, February 4-5, 2008, Dallas, TX. p. 1. Available on-line: http://www.asas.org/southern/meetings_past.asp Interpretive Summary: Abstract Only.
Technical Abstract: Postweaning ADG of 462 calves from Brangus cows and sired by 6 breeds (Bonsmara, Brangus, Charolais, Gelbvieh, Romosinuano) was measured over a 4-yr period to evaluate the impact of preweaning forage, postweaning management, sire breed, and gender on postweaning gain. Preweaning forages were improved forages (common bermudagrass or Old World Bluestem) or native rangeland. Calves from each preweaning forage were weaned at an average 209 d and stratified by sex and sire breed to one of two postweaning management systems (drylot on mixed grain rations or wheat pasture). Gains in each postweaning system were recorded from initiation of fall grazing (early to mid-November) on wheat pasture through late spring for an average of 166 d. Sire breed of calf differences were not consistent across sex of calf, preweaning management and postweaning management (P < 0.10). In general, Bonsmara- and Romosinuano-sired heifers did not perform as well as heifers from other sire breeds in either drylot or wheat pasture postweaning management. Gelbvieh-sired heifers in drylot gained more than Brangus- and Charolais-sired heifers (P < 0.10) but not Hereford-sired heifers. On wheat pasture, few differences were evident among Brangus-, Charolais-, Gelbvieh-, and Hereford-sired heifers. Romosinuano-sired steers had lower ADG on wheat pasture than Hereford- and Charolais-sired steers (P < 0.10) and were numerically lower than steers from other sire breed groups on wheat pasture. However, both Bonsmara- and Romosinuano-sired steers were competitive with calves from other sire breed groups in drylot, with the exception of Charolais-sired steers that outgained other breed groups (P < 0.10). Consequently, the preferred postweaning management based on ADG for the two non-Zebu tropically-adapted breeds would be drylot on mixed rations rather than wheat pasture. Results from these data indicate that genetic differences in postweaning ADG can depend on both preweaning and postweaning environments.