Effect of low-fat corn distillers grains fed at 40 and 70% inclusion on growth performance and meat quality of steers1

Two trials were conducted to examine the effects of 40 and 70% inclusion rate of either dry or wet low-fat (6 to 8%) distillers grains on growth performance and meat quality. Trial 1 used dry distillers grains with solubles (DDGS) and 96 Angus steers. Trial 2 used wet distillers grains with solubles (WDGS) and 216 Angus steers. Steers were stratified by BW to pens, and pens were randomly assigned to 1 of 6 treatments formulated on a DM basis: 1) whole shelled corn, soybean meal, 15% corn silage, fed as a control (CON); 2) 40% DDGS or WDGS, whole shelled corn, 15% corn silage (C40); 3) C40 switched mid-trial to 70% DDGS or WDGS, whole shelled corn, 15% corn silage (40/70); 4) 70% DDGS or WDGS, whole shelled corn, 15% corn silage switched mid-trial to C40 (70/40); 5) CON + soybean meal, isonitrogenous to C40 (N40); 6) CON + corn oil, iso-fat to C40 (E40). In trial 1 DMI was greater (P = 0.02) for N40 and DDGS steers compared with CON for the first 84 d; DMI was lower (P = 0.01) for CON and 40/70 on 168 d. No significant DMI differences (P ≥ 0.32) were observed on d 213. In trial 2 no significant differences in DMI, BW, ADG, or G:F were observed across treatment diets at 142 d except N40-fed steers had reduced (P = 0.01) DMI compared with other treatments. Average daily gain, BW, and G:F at 56 d and 112 d were greatest (P = 0.001) for CON, N40, and E40 steers compared with steers receiving WDGS. Carcass characteristics were not negatively affected (P ≥ 0.06) by level of DDGS in either trial. Neither level of DDGS or WDGS nor CP or fat concentrations had a significant effect on meat quality, fatty acid composition, or lipogenic activity. According to this study, it is possible to increase the inclusion of low-fat DDGS and WDGS in feedlot rations as a percentage of dietary DM above 40%.