Rate of gain during the winter stocker period impacts finishing performance and carcass quality, researchers from West Virginia, Virginia and South Carolina conclude.
Angus-crossbred steers were used in a three-year study to assess the effects of winter stocker growth rate and finishing system on finishing and carcass performance. From December to April, steers were randomly allotted to three stocker growth rates: Low (0.23 kg/day or 0.5 lbs.), Medium (0.45 kg/day or 1 lb.) or High (0.68 kg/day or 1.5 lbs.).
After completion of the winter phase, steers were randomly allotted within each stocker treatment to a corn silage-concentrate or pasture-finishing system. Steers were finished to an equal-time endpoint, regardless of treatment. Upon completion of the finishing period, steers were slaughtered in two groups (half from pasture and half from feedlot cattle each time) and carcass data were collected.
Winter stocker treatment resulted in differences in final body weight, average daily gain (ADG) and ultrasound longissmus (LM) area between all treatments for that phase. Pasture-finished cattle had lower final body weight, ADG, hot carcass weight (HCW), LM area, fat thickness, kidney, pelvic, heart (KPH), dressing percent, USDA Yield Grade (YG) and Quality Grade (QG).
Winter stocker treatment influenced final body weight and HCW, with Low and Medium treatments being less than High. Steers with Low stocker gain had greater finishing ADG. Dressing percent was greater for High than Low, and USDA QG was greater for High than Low and Medium. Carcass LM area, fat thickness, KPH and YG were not influenced during winter rate of gain.
Cattle on Low treatment during winter exhibited compensatory gain during finishing, but were unable to catch the High treatment group regarding body weight or HCW. QG was greater for High treatment than Low or Medium.
Researchers concluded animal performance during the winter stocker period clearly impacts finishing performance, carcass quality and beef production in both pasture- and feedlot-finishing systems, when cattle were finished to an equal-time endpoint.
J.P.S. Neel, et al. 2007. Journal of Animal Science, 85:2012.