Effects of increasing supplementation rates of an extruded distillers’ grains cubes on stocker steer production grazing native range in western Oklahoma

Authors: GRIGSBY, ZANE - Oklahoma State University; Gunter, Stacey; Moffet, Corey; NEW, MARTY - Oklahoma State University; WORTHINGTON, CHARLES - Oklahoma State University; TURNER, DUSTY - Masterhand Milling; BECK, PAUL - Oklahoma State University

Submitted to: Book / Chapter / eBook
Publication Type: Book / Chapter
Publication Acceptance Date: 8/6/2025
Publication Date: 8/6/2025
Citation: Grigsby, Z., S. A. Gunter, C. Moffet, M. New, C. Worthington, D. Turner, and P. A. Beck. 2025. Chapter III: Effects of increasing supplementation rates of an extruded distillers’ grains cubes on stocker steer production grazing native range in western Oklahoma. In: Z. Grigsby (ed.) Supplementation of Stocker Calves Grazing Native Prairie Pastures in Western Oklahoma: Effects on Grazing Performance, Supplemental Efficiency and Subsequent Feedlot Performance and Carcass Characteristics. Stillwater, Oklahoma: Oklahoma State University. p 63-99.

Interpretive Summary: The objective of this research was to test the effects that increasing supplementation rate has on animal performance and supplemental efficiency 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, 263 steers were allocated to 6 uniformly stocked pastures assigned to 3 supplementation rates, 1) Negative Control (NC)- no supplementation; 2) Low Supplement (LS) - 2 lb/animal daily supplemental DDG cubes and 3) Medium Supplementation (MS) – 2 lb/animal daily supplemental DDG cubes. At SPER, 119 steers were allocated to 12 uniformly stocked pastures (4 supplementation treatments), 1) NC; 2) LS; 3) MS and 4) High Supplement (HS) – 6 lb/animal daily supplemental DDG cubes. Increased supplementation generally yielded quadratically greater (P = 0.05) average daily gain but negatively influenced supplemental efficiency during the early summer, however, during late summer as improved performance presented itself as improved supplemental efficiency. Average daily gain for greater supplementation rates increased quadratically (P = 0.05) and body wight gain per acre. 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. This can be especially useful during years of decreased forage availability or forage quality. The response curves observed in this research will allow supplementation decisions to be made based on market conditions.

Technical Abstract: The objective of this research was to test the effects that increasing supplementation rate has on animal performance and supplemental efficiency 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 n=133 (yr 1) and 130 (yr 2) steers were allocated to 6 uniformly stocked pastures assigned to 3 supplementation rates, 1) Negative Control (NC)- no supplementation; 2) Low Supplement (LS) - 0.91 kg/hd/d supplemental DDG cubes and 3) Medium Supplementation (MS) – 0.81 kg/hd/d supplemental DDG cubes. At SPER n=119 were allocated to 12 uniformly stocked pastures (4 supplementation treatments), 1) NC; 2) LS; 3) MS and 4) High Supplement (HS) – 2.72 kg/hd/d supplemental DDG cubes. At SPER blood was collected at each BW collection to analyze BUN and calculate estimated N excretion. Animal performance, forage and blood data were analyzed using PROC MIXED in SAS 9.4 (SAS Inst. Inc; Cary, NC.), as a completely randomized design, animal performance data were analyzed using orthogonal contrasts. Significance was determined at P = 0.05. Increased supplementation generally yielded quadratically greater (P = 0.05) ADG but negatively influenced supplemental efficiency during the early summer, however, during late summer, especially in yr 2 improved performance presented itself as improved supplemental efficiency. However, increased ADG for greater supplementation rates quadratically increased (P = 0.05) BW gain per hectare. 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. This can be especially useful during years of decreased forage availability or forage quality. The response curves observed in this research will allow supplementation decisions to be made based on market conditions.