Opportunities For Storage

Three types of distillers grains can be produced that vary in moisture content. Ethanol plants may dry some or all of their distillers grains to produce dry distillers grains plus solubles (DDGS; 90% dry matter [DM]). However, many plants that have a market for wet distillers locally (i.e., Nebraska) may choose not to dry their distillers grains due to cost advantages. Wet distillers grains plus solubles (WDGS) is 30-35% DM. Modified wet distillers grains plus solubles (MWDGS) is 42-50% DM. It is important to note that plants may vary from one another in DM percentage, and may vary both within and across days for the moisture (i.e., DM) percentage. Figure 1 depicts different forms of distillers grains that may be used by beef producers. There are advantages and disadvantages to each of these feeds.



Another type of feed is wet corn gluten feed (WCGF). There are predominantly two main types of WCGF, which vary in composition and moisture content. In general, these two feeds can be divided into commodity WCGF (40-45% DM) and Sweet Bran (a specific WCGF made by Cargill; 60% DM). These feeds have different storage properties compared to WDGS, and will be discussed briefly throughout this manual.

For a more complete review on feeding of distillers grains and corn gluten feed to beef cattle, the reader is referred to a similar publication produced by the University of Nebraska Lincoln Extension in cooperation with the Nebraska Corn Board. The Utilization of Corn Co-Products publication can be found at: beef.unl.edu or www.nebraskacorn.org.

One challenge with WDGS, MWDGS or WCGF is shelf life. Spoilage will usually begin on the surface of piles of these wet co-products from 3 to 14 days while exposed to air. Shelf life or stability may also vary with ambient temperature, with shorter shelf life existing in hot conditions. While this is avoidable or can be minimized in cases where feed is fed relatively fresh in large feedlots, this may limit the use of WDGS, MWDGS or WCGF for smaller operations. In most cases, milling plants would prefer to deliver coproduct in semi-load quantities (25-30-ton loads) making it difficult for smaller feedlots (less than 1,000- head capacity) to feed a large enough quantity to avoid some spoilage. Likewise, cow-calf producers may want to use WDGS, MWDGS or WCGF, but on a seasonal basis. Seasonal usage is quite difficult for milling plants to manage as their production is fairly constant throughout the year.

Another challenge facing milling plants is the seasonality of cattle numbers in feedlots. Figure 2 depicts the cattle-on-feed numbers for feedlots greater than 1,000 head capacity for the U.S. For the previous five years, cattle-on-feed may fluctuate across months by as much as 1.5 million head. The trend is for fewer cattle in feedlots during summer months. Seasonality of cattle in feedlots is likely even more dramatic in Nebraska than other parts of the U.S. As a result, demand for and price of distillers grains (reported in Figure 2 as DDGS) is usually the lowest during the summer months when cattle-on-feed numbers are lowest. The price for WDGS likely fluctuates even more during the course of a year; however, price data are not available for multiple year comparisons of seasonality in price.



Therefore, it is logical that seasonal users of WDGS, MWDGS or WCGF may choose to store large quantities for use at a later date. Similarly, smaller operations that cannot use semi-load quantities at a rate that prevents spoilage may choose to store these wet co-products. Lastly, any operation regardless of size may choose to purchase large quantities of WDGS or MWDGS in the summer when prices are traditionally the least expensive and feed throughout the remainder of the year. For all of these reasons, storage of wet corn co-products is an important management practice that beef producers may want to learn more about.

We initiated storage tests in 2006 to give producers a "starting point" to store these wet co-products at their operation. Since then, many producers have successfully stored WDGS, MWDGS or WCGF. This manual is intended to give producers a starting point and to share different methods of storing wet co-products.

For more information or to request additional copies of this manual, contact the Nebraska Corn Board at 1-800-632-6761 or e-mail kelly.brunkhorst@nebraska.gov

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Date published: May, 2008