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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Livestock, Forage and Pasture Management Research Unit » Research » Publications at this Location » Publication #427565
Research Project: Integrated Research to Enhance Forage and Food Production from Southern Great Plains Agroecosystems

Location: Livestock, Forage and Pasture Management Research Unit

Title: Effects of increasing supplementation rates of extruded distillers’ grains cubes on stocker steer production grazing native range in Western Oklahoma

Author
item GRIGSBY, ZANE - Oklahoma State University
item Gunter, Stacey
item NEW, MARTY - Oklahoma State University
item WORTHINGTON, CHARLES - Oklahoma State University
item BECK, PAUL - Oklahoma State University

Submitted to: Translational Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2025
Publication Date: 9/19/2025
Citation: Grigsby, Z., Gunter, S.A., New, M., Worthington, C., Beck, P. 2025. Effects of increasing supplementation rates of extruded distillers’ grains cubes on stocker steer production grazing native range in Western Oklahoma. Translational Animal Science. 9. Article txaf128. https://doi.org/doi:10.1093/tas/txaf128.
DOI: https://doi.org/10.1093/tas/txaf128

Interpretive Summary: Growing stocker steers grazing native range pastures in two locations in western Oklahoma were supplemented with increasing rates of a cubed dried distillers grains supplement. Steer gains increased with increasing supplementation rate but at a marginally decreasing rate, resulting in reduced efficiency of supplementation as amount of supplement fed increased. Nitrogen excretion increased with the increasing supplementation rates which could provide benefit to pastures through increased nitrogen uptake by plants. These data suggest that supplementing extruded dried distillers grains cube to steers grazing native range is a viable option to intensify production on stocker operations. If forage value is adequate to support gains increased supplementation rates are likely not economically efficient, however if forage is limiting improved performance may be adequate for positive economic returns. The response curves observed in this research will allow producers to make supplementation decisions based on market conditions.

Technical Abstract: Our objectives to determine the response curve of increasing supplementation rate on animal performance, supplemental efficiency, and N excretion by steers grazing midgrass prairie in western Oklahoma. A 2-year trial was conducted at the Marvin Klemme Range Research Station (Klemme) and the USDA-ARS Southern Plains Experimental Range (SPER). At Klemme steers (n = 133 yr 1, BW = 247 ± 24.5 kg; 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 distillers grains 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 (HS) – daily supplementation rate of 2.72 kg/steer. At SPER blood urea N (BUN) was used to calculate N excretion. Data were analyzed by year and experimental site as a completely randomized design. Least-squares means were separated using orthogonal polynomial contrasts. In both years at Klemme increased supplementation rate resulted in a linearly greater (P = 0.01) overall ADG with no difference (P = 0.16) in supplemental efficiency. At SPER overall ADG increased linearly (P < 0.01) in yr 1 but quadratically (P = 0.05) in yr 2 with increasing supplementation rate that negatively influenced supplemental efficiency with a quadratic response (P = 0.01) in both years. As supplementation rate increased BUN followed suite (P = 0.04) resulting in increasing calculated urinary and fecal N output. These data suggest that supplementing extruded DDGS cube to steers grazing native range is a viable option to intensify production on stocker operations. If forage value is adequate to support gains increased supplementation rates are likely not economically efficient, however if forage is limiting improved performance may be adequate for positive economic returns. The response curves observed in this research will allow producers to make supplementation decisions based on market conditions.