Date Full Report Received


Date Abstract Report Received



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Use of alternative feedstuffs in feed formulation is increasingly important with elevated grain prices and the availability of alternative ingredients, largely corn-dried distillers grains with solubles (C-DDGS). Changes are constantly occurring in the corn milling industry with the most recent technology, oil extraction, resulting in C-DDGS with a wider range of energy and nutrient composition. Past research has focused on determining the digestible and metabolizable energy (DE and ME, respectively) concentration of C-DDGS, and generation of prediction equations for DE and ME based upon compositional analysis. However, a further improvement in relating animal growth to dietary energy is to formulate diets on a net energy (NE) basis. While NE is commonly used in Europe, nutritionists in the U.S. have been reluctant to adapt this technology due to lack of information on the NE value of specific ingredients and data supporting its validity in U.S. style feeding programs.

The objectives of the following studies were to: 1—obtain sources of C-DDGS varying in energy and nutrient content and determine DE, ME, and NE and to determine if the composition of these C-DDGS samples could be utilized to develop or refine current DE and ME prediction equations, and to generate a NE prediction equations; 2—to obtain a single source of C-DDGS and using recent data to accurately estimate its NE value, formulate diets with graded levels of C-DDGS, but equal levels of dietary NE and determine the impact on pig performance and carcass dressing percent when fed at a commercial production facility.

The results of the experiments conducted at a university research facility indicate that, although C-DDGS composition can vary and subsequent DE, ME, and NE also varies, a wider range in ingredient composition and DE, ME, and NE values are necessary to generate prediction equations. Data obtained indicated that on average, the C-DDGS contained 3,931, 3,793, and 2,133 kcal of DE, ME, and NE/kg DM, respectively. These DE and ME values are within the ranges reported in the literature; with the NE value reported herein being the first reported for C-DDGS.
Based upon this data and a review of relevant literature, diets in the field study were formulated to contain 0, 10, 20, and 30% C-DDGS, but with equal levels of dietary NE across all levels of C-DDGS. Diets were fed to 3 barns of pigs at the same location, each containing 48 pens and 20 pigs per pen (2,880 pigs total). Overall, there were no differences noted for average daily gain, average daily feed intake or feed efficiency among pigs fed the different C-DDGS levels. In addition, there was no effect of dietary treatment on dressing percent, suggesting that the estimates of NE, AA, and minerals utilized for feed formulation were relatively accurate. The data presented herein provide valid estimates of the DE, ME, and NE of C-DDGS and support the use of formulating diets on a NE basis, which is especially important in utilizing alternative feedstuffs in swine diet formulation.
For further information, contact Dr. Brian Kerr, USDA-ARS, Ames, IA, by phone (515-294-0224) or email (brian.kerr@ars.usda.gov).
Key Findings:
• Corn–dried distillers grains with solubles (C-DDGS) is an excellent source of DE and ME for growing pigs, with the DE (3,931 kcal/kg DM) and ME (3,793 kcal/kg) values being similar to values reported in the literature.
• Net energy (NE) value determined by this research are the first reported in the literature for C-DDGS, with the value of 2,133 kcal/kg DM being lower than the 2,622 kcal/kg DM reported in the 2012 Swine NRC. This energy value will be critical in formulating feeds on a NE basis in order to maintain pig performance.
• When formulated on an equal NE basis, feeding up to 30% C-DDGS to pigs in a field situation had no impact on pig performance or dressing percent, indicating that the estimates of NE , as well as AA and mineral levels, utilized for corn, soybean meal, soybean oil, and C-DDGS utilized in formulating these feeds were relatively accurate.