Effects of increasing supplementation rates of extruded distillers’ grain cubes on stocker steers production grazing native range in Bessie, OK and Fort Supply, OK during the summer months in 2021 and 2022

The objectives of this study were to determine the response curve of increasing supplementation rate with extruded distillers’ grains (DDG) cubes for animal performance and supplemental efficiency by steers grazing midgrass prairie in western Oklahoma. A 2-year trial was conducted at the Oklahoma Agricultural Experiment Station, Marvin Klemme Range Research Station (Klemme), Bessie, Oklahoma and the USDA-ARS, Southern Plains Experimental Range (SPER), Ft. Supply, Oklahoma, both in western Oklahoma during the summers of 2021 and 2022. At Klemme, steers (n = 133 Yr 1, BW = 247 ± 24.5 kg; Yr 2, n = 134, BW = 264 ± 29.1 kg) were allocated to 6 pastures in Yr 1 and 7 pastures in Yr 2 which were assigned to three daily supplementation rates of DDG cubes: 1) Negative Control (NC)- no supplementation; 2) Low Supplement (LS) - 0.91 kg/steer and 3) Medium Supplementation (MS) – 1.82 kg/steer. At Klemme, steers were stocked at 2.0 ha/steer in yr 1 and 2.8 ha/steer in yr 2. At SPER steers (n=119 each year; Yr 1, BW = 295 ± 28.8 kg; Yr 2, BW = 294 ± 25.7 kg) were allocated to 12 pastures stocked at 2.0 ha/steer with pastures assigned to: 1) NC; 2) LS; 3) MS and 4) High Supplement – daily supplementation rate of 2.72 kg/steer.