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.

本研究旨在明确俄克拉荷马州西部中草草原放牧阉牛时，膨化蒸馏谷物（DDG）块的补充饲喂量递增对其生产性能及补充饲喂效率的响应曲线。试验于2021年和2022年夏季在俄克拉荷马州西部的两处地点开展，分别为位于贝西的俄克拉荷马州农业试验站马文·克莱姆牧场研究站（Klemme站），以及位于福特萨普莱的美国农业部农业研究服务局（USDA-ARS）南部平原试验牧场（SPER）。在Klemme站，第一年试验阉牛共133头，初始体重为247±24.5 kg；第二年共134头，初始体重为264±29.1 kg，分别被分配至6个（第一年）与7个（第二年）放牧牧场，分为3种每日DDG块补充饲喂方案：1）阴性对照组（NC）：无补充饲喂；2）低补充组（LS）：每头阉牛每日补充0.91 kg；3）中等补充组（MS）：每头阉牛每日补充1.82 kg。Klemme站的载畜量为第一年2.0公顷/头，第二年2.8公顷/头。在SPER站，每年试验阉牛均为119头，第一年初始体重为295±28.8 kg，第二年为294±25.7 kg，试验阉牛被分配至12个放牧牧场，载畜量为2.0公顷/头，分为4种补充饲喂方案：1）阴性对照组（NC）；2）低补充组（LS）；3）中等补充组（MS）；4）高补充组：每头阉牛每日补充饲喂量为2.72 kg。