Effects of Digestible Fiber and Yellow Grease Supplementation to Steers Grazing Small-Grain Pastures on Grazing and Feedlot Finishing Performance1

A performance experiment was replicated in 2 yr to evaluate the effects of yellow grease supplementation on grazing and subsequent feedlot performance and carcass characteristics of beef steers grazing small-grain pasture. British crossbred steers (yr 1 = February 15, 2006, n = 45, initial BW = 329 ± 14.8 kg; yr 2 = February 24, 2007, n = 45, initial BW = 276 ± 20.1 kg) were allowed to graze irrigated small-grain pasture. During the grazing periods, steers received 1 of 3 supplements: 1) mineral supplement (MS) offered at 114 g/animal daily, 2) MS plus a supplement based on soybean hulls and wheat middlings (MF) offered at 0.50% of BW, and 3) MF plus yellow grease supplement (MFY), consisting of the supplement offered at 0.50% of BW and yellow grease offered at 0.125% of BW. Grazing ADG was greater (P = 0.01) for the steers receiving supplement compared with those receiving only MS (1.09, 1.25, and 1.31 ± 0.06 kg/d, for MS, MF, and MFY, respectively). Feedlot ADG (P = 0.47; 1.38, 1.45, and 1.40 ± 0.04 kg/d for MS, MF, and MFY, respectively) and DMI (P = 045; 10.6, 104, and 10.1 ± 0.26 kg/d for MS, MF, and MFY, respectively) were not affected by the supplemental treatment offered during grazing. Carcass characteristics were not altered (P ≥ 0.41) by supplemental treatments. In conclusion, adding yellow grease to the digestible fiber supplement did not further improve performance on pasture or in the finishing phase.