The Use of High Distillers Grains and Nutrient Management in Beef Feedlots

Two experiments using calves fed 173 d from November to May (WINTER) and yearlings fed 145 d from May to September (SUMMER), were conducted to evaluate the effects of feeding a high inclusion level of both wet distillers grains plus soluble (WDGS) and wheat straw or a corn control diet (CON) on ADG, F:G, manure N, and N losses. In each experiment, 128 steers (WINTER: 311 ± 10 kg, SUMMER: 365 ± 5 kg) were stratified by BW and assigned randomly to 16 pens (8 steers/pen). Four treatments were tested as a 2X2 factorial with factors being diet and pen cleaning frequency (monthly or at the end of the feeding period). Diets consisted of 85% corn, 5% molasses, and 5% wheat straw (CON) or 70% WDGS and 25% wheat straw (WDGS+straw). Both diets contained 5% supplement. In both the WINTER and SUMMER experiments, the CON treatment had greater DMI, ADG, HCW, marbling and fat depth. There was greater N intake and N excretion for both the WINTER and SUMMER experiments on the WDGS+straw however, for the WINTER experiment, there was not a difference in the amount of N in the manure nor for pen cleaning frequency. In the SUMMER experiment, cleaning pens monthly almost doubled DM, OM, and N removed in manure. There was a tendency for the WDGS+straw treatment to have greater N loss than the CON treatment in the WINTER experiment and a significant