Thin stillage from wheat-based ethanol production as a nutrient supplement for cattle grazing crested wheatgrass pastures

Abstract

An 84-d trial was conducted to evaluate the use of thin stillage from wheat based ethanol production as a nutrient supplement for cattle grazing crested wheatgrass. Forty medium-frame steers were allotted to eight CWG pastures (5 pasture−1) and supplied with either water or thin stillage as a fluid source. Measurements included daily intake of fluid, biweekly weight gains, start and end of test ultrasonic backfat measurements, and blood plasma samples on days 42, 56, and 70 of the trial. Samples of thin stillage and biweekly clippings of the CWG pastures were collected throughout the trial for analysis. Thin stillage averaged 8.4 ± 0.35, 48.5 ± 1.83, 9.6 ± 1.63, 34.5 ± 4.55, and 3.4 ± 0.44% (DM basis) CP, EE, NDF and ADF, respectively. Cattle with access to thin stillage exhibited superior (P < 0.05) weight gains from day 42 through day 84 of the trial. Cumulative weight gains were 1.39 ± 0.14 and 0.91 ± 0.27 kg d−1, respectively, for the thin stillage and water fed cattle (P < 0.05), an increase of 53%. Fluid intake of the cattle on stillage was 48.2 ± 2.7 L d−1 or 67% greater (P < 0.05) than that for animals on water (28.9 ± 1.53 L d−1). Daily DM intake from thin stillage estimated from fluid intake was 4.1 kg. The superior liveweight gain of cattle fed thin stillage was reflected in higher (P < 0.05) backfat levels at the end of test (2.51 vs. 0.6 mm) and higher (P < 0.05) plasma urea, Mg, and P levels. The results of this study indicate that thin stillage from wheat-based ethanol production is a valuable nutrient source for cattle grazing CWG. Key words: Thin stillage, wheat, crested wheatgrass