Project Number: 6209-31630-003-33
Start Date: Sep 15, 2011
End Date: Sep 14, 2015
Exp. 1. Determination of net energy values and enteric methane production via indirect calorimetry. Dietary treatments will include low-fat, medium-fat, and high-fat DDG included at 30% of the diet compared to a steam-flaked corn-based control containing no DDG. Eight steers will be trained to the calorimetry system. Four steers will be fed ad-libitum and four will be limit-fed at maintenance in order to calculate NEm and NEg. Each steer will receive each diet in a Latin Square design. The indirect respiration calorimetry system used will consist of four chambers constructed of a metal pipe frame and Lexan sheets. Air will be analyzed for oxygen, carbon dioxide, and methane. Heat production will be calculated from oxygen consumption, carbon dioxide and methane production, and urinary nitrogen (N) excretion using the equation of Brouwer (1965). Each of the periods of the Latin square will consist of an initial 14-d diet adaptation and 7 d of fecal, urine, and gas exchange collections. Urine and feces from each steer will be weighed daily to determine total tract digestibility. Exp. 2. An individual steer finishing study will be conducted using Calan headgates. Three treatments will be used to determine the effects of treating sorghum WDGS with buffered enzymes on animal performance and carcass characteristics. The treatments will include a finishing diet containing 45% sorghum WDGS, 45% sorghum WDGS treated with enzyme, and 45% WDGS with 10% added limestone (to raise pH), then treated with enzyme. There will be 54 steers and 3 treatments (18 steers per treatment). Steers will be fed for 150 to 200 days. Exp. 3. To cooperate with USDA-ARS in conducting respiration calorimetry studies on 1) the use of enzyme treated distillers grains on energy metabolism and enteric methane emissions of steers fed finishing diets, 2) effect of degree of steam flaking (24 or 28 lb/bu) and dietary distillers grain concentration (0, 15 or 30%) on energy metabolism and enteric methane production of finishing calves, and 3) effects of supplementation strategies on energy retention and enteric methane production of steers fed high forage diets.