Using Distillers Grains in Beef Cattle Diets
Jeff Pastoor, Senior Cattle Consultant
Land O'Lakes Beef Feeds
The availability of distillers grains has gone up dramatically in the past 5 years with the construction of dry-milling ethanol plants across the upper Midwest. Distillers grains provides the beef industry with a nutrient dense and palatable feed that can lower the cost of gains in many operations.
Distillers grain research has been done primarily at Iowa State University, South Dakota State University, and the University of Nebraska. Land O’Lakes has also had practical experience with dry corn milling byproducts through work with local coops in Iowa, South Dakota, and Nebraska that have facilitated dry corn milling plants.
Distillers grains can have positive impacts on feedlot diets, beyond the cost effectiveness. Those that most commonly come to mind are:
Add moisture to dry diets
Improve feed intakes
Add non-starch digestible energy
Raise the protein content of the diet.
Initial University research shows that the energy value of distillers grains to be 100-120% that of #2 corn on dry matter basis. However, University research initially indicated that wet corn gluten feeds would be 105-110% the energy value of corn, while field experience has shown this to be 93-95%. As a result, for ration balancing purposes we are putting wet distillers grains at 100-103% of #2 corn. So far, closeouts have shown this to be fairly accurate.
Also based on our experience with corn gluten feeds, the dried distillers grains will be lower in energy, about 93% the energy of wet distillers grains. The drying process drives off some of the energy containing ethers as well as making some of the fiber less digestible.
The benefit of distillers grains is that the energy comes from non-starch sources such as fat and fiber. Digestible fiber is a benefit to the rumen health, as compared to starch fiber digestion results in less reduction of rumen pH. Pre-fermentation at the plant might also be contributing to the better digestibility of the distillers grains. We need to keep an eye on the fat level of the distillers grains. It is generally recommended that fat be limited in the diet to 5-6% to prevent rumen upset from fiber coating. We know from the dairy industry that these fats can also tie up calcium and magnesium in the rumen, reducing their availability.
Distillers Grains are high in protein (28-30% on a DM basis). This protein will be high in UIP (by-pass protein) while feedlot cattle need high levels of DIP in the diet to optimize rumen function. Feeding enough distillers grains to meet Crude Protein requirements will not meet the DIP requirements. Too much UIP and too little DIP effectively starves the rumen microbe population and results in lost efficiency and performance. Supplemental feeding of urea as NPN through the balancer is recommended for optimum performance and cost of gain.
Based on research done at SDSU and ISU, our suggested feeding levels for distillers grains products would be: Wet Distillers Grains at 12-15% of the diet dry matter (8 - 11#/day) Dried Distillers Grains at 12-15% of the diet dry matter (2.5- 3.5#/day) Corn Syrup or CCDS at 4-5% of the diet dry matter (3.5 - 5#/day)
For the feedlot, distillers grains need to be priced relative to the value of corn, soybean meal, and urea. Producers also need to factor in the costs of shrink, spoilage, storage, and handling; these are estimated at $5-10/ton. For example, with corn at $2.25, HiPro soybean meal at $300/ton, feed grade urea at $360/ton, and shrink/storage/handling at $5/ton distillers grains are worth:
$38/ton delivered for wet distillers grains (40% DM)
$112/ton delivered for dried distillers grains
These are breakeven values, feedlots will likely want to pay under this to get an ROI on their purchase.
One other area of consideration is the impact on manure from distillers grains and corn gluten feeds. Since corn processing concentrates non-starch nutrient fractions into the by-product, there is a real concern about excess nitrogen and phosphorus levels in the manure of cattle fed these by-products. Other nutrients (such as trace minerals) are also concentrated, but we do not yet know the actual impact on the environment. With a new environmental emphasis on phosphorus loads in manure, in some areas it could take 1 acre of land per feedlot head capacity to apply manure from cattle fed corn co-products.