Location: Livestock Nutrient Management Research2012 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 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 distiller's grains on potential nitrogen and phosphorus losses from feedyards, and (3) assess the effects of the extent of dietary corn processing and wet distiller's grain concentration on energy metabolism of beef cattle.
1b. Approach (from AD-416):
The feeding value of wet distiller's grains with solubles for finishing beef cattle can be affected by the ratio of distiller's grain (i.e. wet cake) and solubles. However, to our knowledge, no research studies have been conducted to evaluate the effects of the cake:solubles ratio on animal performance when diets are based on steam flaked corn. These comparisons needed by nutritionists and feedlot managers so they can value different sources of distiller's grains. We propose a comparison involving combining the grains and solubles from a corn-ethanol plant at different ratios. 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 an ethanol plant in the area 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 20% wet corn distiller's grains (i.e., wet cake) plus no condensed corn solubles, 3) a diet with 15% wet cake plus 5% condensed corn solubles, and 4) a diet with 10% wet cake plus 10% condensed corn solubles. Steers will be fed in open lot pens and slaughtered when backfat thickness is visually estimated to be 0.5 inches. Dry matter intake and averaged daily gain will be measured. Standard carcass measurements will be collected at slaughter. ARS personnel will obtain samples of diets, feed ingredients, fresh feces, and air dried manure for determination of nutrient excretion, and nitrogen volatilization losses. In a calorimetry study, six steers will be used in a 6 x 6 Latin square design. Treatments will be in a 2 x 3 factorial with 2 degrees of corn steam flaking (bushel weights of 24 or 28 lbs.) and three concentrations of wet distiller's grains (0, 15 or 30% of diet dry matter). Using open circuit, indirect respiration calorimeters, carbon dioxide and methane production and oxygen consumption of individual steers will be determined. Energy digestibility, heat production, energy retention, and dietary energy values will be determined.
3. Progress Report:
We started growing a portion of the cattle for this study after a receiving study that concluded in August 2011. However, the sorghum distiller's grains supplier had switched to corn grain and did not know when they would resume using predominantly sorghum. Thus, those cattle were diverted to a different study. We intend to start the study in early 2013, when the supplier expects to have sorghum distiller's grain available. The portion of the budget utilized thus far will be offset by local funds in order to complete all aspects of the study as originally planned. Treatments will include a control ration without distiller's byproducts, 15% corn distiller's grains with an additional 5% corn distiller's soluble, 15% sorghum distiller’s grains with 5% sorghum distiller’s soluble, and 20% sorghum distiller's grains. The study will involve 9 pen replicates, with each pen containing up to 10 animals. The ADODR and lead investigators are in regular contact via e-mail, phone, and face-to-face contacts. The ADODR monitors cooperator expenditure of funds through semi-annual reports from the cooperator and via contacts with the lead investigator.