138 Investigation of Supplementation Rates for Extruded 100% DDGS Cube on Native Range in Northwest Oklahoma

Abstract A 2-year trial was conducted at the USDA ARS- Southern Plains Experimental Range (SPER), near Fort Supply, Oklahoma to test effects of supplementing 100% DDGS cubes different rates steers on native range during summer grazing period. The purpose these trials analyze effect that increased levels supplementation have performance and supplemental efficiency. In both 2021 2022, (294 ± 32 kg, n=118) were allocated 4 season-long (Mid-May until Late September) treatments, 1) Negative Control, (NC), no supplement with ad libitum access lose mineral, 2) Light Supplement, (LS), 0.91 kg∙animal-1∙day-1, 3) Medium (MS), 1.81 4) High (HS), 2.72 kg∙animal-1∙day-1. All pastures (n = 12) stocked 2.02 ha/animal, forage biomass data nutritive value collected beginning middle end summer. Data analyzed using PROC MIXED linear quadratic contrasts made GLM in SAS 9.4. Early season ADG followed a pattern (R2 0.47, P 0.0009) for HS, MS, LS which 0.55, 0.48, 0.37 0.06 kg/d greater (P < 0.001) than NC, respectively. efficiency 0.18 0.016 kg added gain per but decreased 0.79, supplementation. MS HS 0.12 0.09 0.02 gain/kg supplement. 0.25, 0.13, 0.11 0.05 ≤ 0.03) linearly 0.43, 0.0048) 0.07, 0.04, 0.01 Overall greatest steers, 0.41, 0.16, 0.03 0.01) LS, Supplemental over entire 0.91, 0.0001), we saw decrease These suggest increases decreases when quality is greater. However, as declines becomes less palatable later summer, appear supply energy protein lacking continue promote increase