Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2003
Publication Date: 1/1/2004
Citation: Hersom, M.J., Krehbiel, C.R., Horn, G.W., Phillips, W.A. 2004. Effect of live weight gain during winter grazing on subsequent feedlot performance, carcass characteristics and body composition. Journal of Animal Science 82:262-272. Interpretive Summary: Stocker calves that achieve a high rate of gain during the winter wheat grazing season have traditionally been discounted in price because of anticipated decreased performance during the subsequent feedlot phase of production. Experiments were conducted to examine the effect of previous rate gain during winter grazing on subsequent growth. Our data indicates that it is not appropriate to anticipate decreased performance by high gaining wheat pasture cattle and that differences in initial body composition of cattle when placed on feed can be effectively mitigated if they are fed to the same compositional endpoint.
Technical Abstract: Two experiments were conducted to examine the effect of previous BW gain during winter grazing on subsequent growth performance, carcass characteristics, and change in empty body composition during the feedlot finishing phase. Steer calves were randomly assigned to one of the following three treatments: 1) high rate of BW gain grazing winter wheat (HGW), 2) low rate of BW gain grazing winter wheat (LGW) or 3) grazing dormant tallgrass native range (NR) supplemented with 0.91 kg/d of a 41% CP supplement. Winter grazing live BW gains (kg/d) for HGW, LGW, and NR steers were, respectively, 1.20, 0.61, and 0.16. At the end of winter grazing steers were fed a high-concentrate diet to a common backfat endpoint. Gain efficiency during the finishing phase did not differ (P > 0.05) among treatments, but DMI (% of mean BW) for NR and LGW was greater (P < 0.05) than HGW steers. Differences in ADG during winter grazing and initial body fat content did not influence rate of live or empty body weight gain or gain efficiency during finishing. Initial differences in carcass and empty body fat content were mitigated by feeding steers to a common backfat thickness endpoint.