Productivity of Hereford, highgrade Simmental and Belmont Red beef [cattle] herds in central Queensland, 1. Pregnancy, calving and weaning rates
1992
Burns, B.M. (Queensland Dept. of Primary Industries, Theodore (Australia)) | Tierney, T.J. | Rudder, T.H. | Howitt, C.J. | O'Rourke, P.K. (Queensland Dept. of Primary Industries, Brisbane (Australia)) | Esdale, C.R. (Queensland Dept. of Primary Industries, Biloela (Australia))
A total of 24 Hereford, 23 highgrade Simmental and 26 Belmont Red single sire joining groups were compared over 4 joining seasons. The Belmont Red herd had the highest pregnancy, calving and weaning rates (87, 85 and 81 percent, respectively). Hereford and highgrade Simmental herds had similar pregnancy (78 v. 75 percent) and calving (76 v. 73 percent) rates, but the Hereford herd had higher weaning rates (68 v. 60 percent). Reproductive rates were affected by seasonal conditions, being lowest in the 1982-83 joining year which followed drought conditions. Depression in productivity, due to seasonal conditions, was greater in the Hereford and highgrade Simmental herds than in the Belmont Red herd. Pre-natal foetal losses from established pregnancy to the start of calving averaged 2.5 percent of pregnant cows, with no breed effect. Peri-natal calf losses, from the start of calving to 7 days post calving, were lowest in Belmont Red (2.9 percent) and higher in highgrade Simmental (10.2 percent) than Hereford (5.8 percent). Death rates of primiparous cows were Belmont Red 2.0, Hereford 5.8 and highgrade Simmental 11.8 percent. Amongst multiparous cows, death rates were Belmont Red 0.9, Hereford 2.2 and highgrade Simmental 2.9 percent.
Показать больше [+] Меньше [-]