Effect of Backgrounding and Feedlot System Strategies on May-Born Steer Performance

A 6-yr study examined the effects of differing backgrounding and feedlot systems on May-born steer performance was conducted at Gudmundsen Sandhills Laboratory (GSL), Whitman, NE, and West Central Research and Extension Center (WCREC), North Platte, NE. Weaned steers (n = 392) were blocked by BW and randomly assigned to one of two backgrounding treatments: meadow hay ad libitum and 1.81 kg/d of a 33% CP (DM) supplement (HI) or allowed to graze dormant sub-irrigated meadow with 0.45 kg/d supplement (LO). Steers were placed on backgrounding treatments for 136 d from January to May. In May, one-half of the steers from each backgrounding treatment were placed in the WCREC feedlot system (CALF). The remaining steers grazed upland range at GSL and were transported to the WCREC feedlot mid-September. In yr 2 – 5, steers were fed in a GrowSafe (GrowSafe Systems Ltd., Airdrie, AB, Canada) feeding system. Over the backgrounding period, HI steers had a greater (P < 0.01) ADG (0.64 vs. 0.35 ± 0.03 kg/d, HI vs. LO) and May BW (275 vs 244 ± 2 kg, HI vs. LO). Feedlot entry BW differed (P = 0.02) by combination of development and feedlot system, with HI-YRL steers having the greatest BW (353 ± 3 kg), followed by LO-YRL (341 ± 3 kg), HI-CALF (264 ± 3 kg), and LO-CALF (237 ± 3 kg). Gain:Feed ratios were improved (P = 0.01) in LO steers (0.16 vs. 0.15 ± 0.002 kg:kg, LO vs. HI). At slaughter, HCW was greater (P < 0.01) for HI development (419 vs. 407 ± 3 kg, HI vs. LO) and YRL feedlot system (426 vs. 401 ± 3 kg, YRL vs. CALF). Yield grade was greater (P = 0.04) for the YRL system (3.3 vs. 3.2 ± 0.05, YRL vs. CALF). Marbling score tended to be greater (P = 0.10) for LO development (480 vs. 467 ± 6; LO vs. HI) and was greater (P < 0.01) for YRL system (490 vs. 457 ± 6, YRL vs. CALF). Alternative backgrounding and feedlot systems impacted steer feedlot and carcass traits.