Location: Livestock Nutrient Management Research2010 Annual Report
1a. Objectives (from AD-416)
The objectives of this cooperative research project are to (1) assess the effects of the wet cake to solubles ratio of sorghum- and corn-based distiller's grains with solubles on the performance and carcass characteristics of finishing beef cattle, (2) assess the effects of the wet cake to solubles ratio of sorghum- and corn-based distiller's grains on potential nitrogen and phosphorus losses from feedyards.
1b. Approach (from AD-416)
Few comparisons have been conducted that directly compare the feeding value of sorghum- and corn-based distiller's grains within the same study. These comparisons are extremely important for nutritionists and feedlot managers to value each ingredient. However, those previous comparisons also include differences in the ratio at which the distiller's grains (i.e., wet cake) and the solubles are combined at the plant. We propose a more pure comparison involving combining the grains and solubles from sorghum and corn at constant ratios at the feedyard to eliminate the influence of those plant procedures on feeding value. In a feeding trial, 36 pens of beef steers (approximately 432 head with an average starting body weight of 650 lbs) will be fed one of four experimental diets with nine pens (12 head per pen) per treatment. Wet cake and solubles will be purchased separately from two ethanol plants in the area (one uses corn exclusively and the other uses sorghum exclusively) and will be mixed in the desired ratios at the WTAMU experimental feedlot. Experimental diets will include: 1) a control diet based on steam-flaked corn (SFC) with no distiller's grains or distiller's solubles, 2) a diet with 15% wet corn distiller's grains (i.e., wet cake) plus 5% condensed corn solubles, 3) a diet with 15% wet sorghum distiller's grains (i.e., wet cake) plus 5% condensed sorghum solubles, and 4) a diet with 20% sorghum wet cake. Steers will be blocked by initial weight and each block of cattle will be shipped to slaughter when backfat thickness is visually estimated to be 0.5 inches or more than 5% heavy carcasses are anticipated. Standard carcass measurements will be collected at slaughter. When the first group of cattle is shipped to slaughter, USDA-ARS personnel will obtain samples of diets, feed ingredients, fresh feces, and air dried manure for determination of nutrient excretion, and nitrogen volatilization losses. Cattle will be implanted as appropriate, based on the expected length of the feeding period. Ingredient samples will be collected weekly for dry matter (DM) determination (daily for SFC and wet distiller's grain with soluble) and a second sample will be composited at 28-d intervals before subsequent analysis. Each month, diet density will be determined and used to calculate volume of feed delivered. Diet samples will be collected weekly for DM determination followed by compositing to 28-d intervals until analyzed for crude protein, acid detergent fiber, neutral detergent fiber, acid detergent insoluble nitrogen, ether extract, ash, and minerals. Data will be analyzed using mixed model procedures; block will serve as random effects.
3. Progress Report
The feeding pens that are needed for this study have been reserved and are expected to become available by March 2011. They will not be available until this time because other studies, funded by other grants, pre-dated the funding for this agreement. The graduate student that will conduct this study has been hired,and all the capabilities are present to execute the experiment. The ADODR and lead investigators are in regular contact via e-mail, phone, and face-to-face contacts. The ADODR monitors cooperator's expenditure of funds through semi-annual reports from the cooperator and via contacts with the lead investigator.