10 November 2009

4 minute read

North America

There are multiple products available which include: dry distillers grains plus solubles (DDGS), wet distillers grains plus solubles (WDGS), and wet corn gluten feed (WCGF). The use of them varies greatly from operation to operation depending on distance from ethanol plants, other feed byproducts, size of operation and price. As price increases in distillers grain, inclusion levels decrease.

The Extension staff say that relatively small amounts of DDG are used in Nebraska feedlots for multiple reasons. The majority of the time and almost all the plants in Nebraska produce these byproducts in the wet form (35 to 60 per cent dry matter (DM); i.e., 65 to 40 per cent water). This is a great thing for Nebraska because wet feeds are less costly for the plants (they don't have to spend the money or energy to dry the feed from the wet form to make DDGS), and the wet feeds are actually a better feed for feedlot cattle. Feeding in the wet form creates some challenges, but these can be overcome.

There are two main approaches to using these byproducts. One method is to feed enough to just meet the protein needs of the cattle. The inclusion levels in this situation are usually 10 per cent to 15 per cent of the diet DM or less than 3 pounds of DM per steer each day. If feedlots use the DDGS, then it is almost always used as a protein supplement only. However, this could change in the future if more is available at a lower price. We are currently conducting studies with DDGS because they may be a better fit for smaller operations and we are also studying its use in forage situations. The price is usually higher for DDGS because when it is dried, it is usually marketed as a protein supplement and priced relative to soybean meal. This is commonly used by dairies as a protein supplement, but there are some research available on swine and poultry use at low concentrations in the diet.

The second method or approach to use of ethanol byproducts is to replace energy or corn. Inclusion levels as an energy replacement are usually 10 per cent to 40 per cent of the diet for WDGS. WCGF could also be used this way and it is common to see levels of 10 per cent to 40 per cent of this byproduct. In terms of pounds, this would be feeding 4 to 8 pounds per day of DM. Our data on use as an energy source are provided in a report available under "byproducts" on the http://beef.unl.edu website. This approach works well.

Extension specialists say that average inclusion levels are approximately 10 per cent DDGS (if using at all, but perhaps 10 per cent or less of the cattle), 15 per cent to 25 per cent inclusion for WDGS, and 20 per cent to 30 per cent inclusion for WCGF. 

There are some concerns about dealing with this extra phosphorus (P). Because corn contains approximately 0.3 per cent phosphorus, the feed byproducts contain between 0.8 per cent and 1.0 per cent P depending on how it is made, how much solubles are put back on, or whether you are talking about WCGF. In some situations (only DDG or WDG without solubles), you may see feeds as low as 0.4 per cent to 0.5 per cent P. Feedlots are being regulated to monitor how nutrients are spread in manure relative to amounts of N and P that are spread on land acres. In some situations, we have applied more P than the crop needs, which can create challenges with runoff from fields. This is not a challenge in the feedlot where runoff is already controlled, it is more of a challenge when manure is spread.

From a state-wide perspective, Nebraska is in a very good position. We export 40 per cent of our corn, which means 40 per cent of the P in corn leaves Nebraska. Our challenge is in local areas. As a feedlot industry, we have had this challenge before byproducts were available, and now with feeding more and more byproducts, this challenge is certainly greater. We have been working on this to determine what does it cost the producer to spread manure further. For example, if it cost the feedlot more to spread manure when byproducts are used compared to the advantage of using byproducts in terms of cattle profitability, then feedlots should not use them. Our data suggests it is still quite economical ($15 to 25 return per head finished) to use byproducts compared to increased cost of spreading manure further ($1 to 3 per finished animal). However, this assumes you can go further to the next field. So, we have challenges in local areas and cattlemen are quite concerned about how to manage this, but we are working on it. There is also some research under way at UNL to remove P from byproducts to decrease the level that would be fed when they are used as a feed.