Effect of live weight gain of steers during winter grazing: I. Feedlot performance, carcass characteristics, and body composition of beef steers

摘要: Two experiments were conducted to examine the effect of previous BW gain during winter grazing on subsequent growth, carcass characteristics, and change in body composition feedlot finishing phase. In each experiment, 48 fall-weaned Angus x Angus-Hereford steer calves assigned randomly one three treatments: 1) high rate wheat (HGW), 2) low (LGW), or 3) dormant tallgrass native range (NR) supplemented with 0.91 kg/d cottonseed meal. Winter ADG (kg/d) for HGW, LGW, NR steers were, respectively, 1.31, 0.54, 0.16 (Exp. 1.10, 0.68, 0.15 2). At end grazing, four selected from treatment measure initial characteristics chemical carcass, offal, empty body. All remaining fed a high-concentrate diet common backfat point. Six final composition, measured all steers. Initial fat mass proportion greatest (P < 0.001) intermediate least both experiments. Live efficiency phase did not differ = 0.24) among treatments, but DMI (% mean BW) LGW was greater 0.003) than HGW Final empty-body 0.25) treatments Exp. 1. 2, (g/kg) 0.03) Accretion fat-free organic matter 0.004) 1, 0.22) 2. Fat accretion 0.19) 0.05) Heat production by 0.02) 1 Differences content affect live finishing. Feeding thickness point mitigated differences content. However, maintenance energy requirements increased nutritionally restricted that wintered range.