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Q: Are there any differences between wet and dry distillers' grains?

A: Although it may seem unnecessary to mention, the difference is the dry matter content of the distillers' grains types is important. Wet distillers' grains will run about 35% dry matter whereas dry distillers' grains will run about 90% dry matter. There is a new product out called modified distillers' grains that usually runs about 45% dry matter, but all of these dry matter values vary some from plant to plant. The dry matter content is important because it is the dry matter portion of the feed that contains the energy and nutrients the animal needs. Therefore properly formulated rations will be done a dry matter basis. What this means is that you will need to feed a lot more as fed wet distillers' grains than as fed dry distillers' grains. It also means that there is added wear and tear on feed equipment because you have to load and deliver more as fed feed. From a feedlot cattle performance standpoint, a published review of data from the University of Nebraska suggests that optimum feed conversion is achieved with a higher inclusion rate of wet distillers' grains that with dry distillers' grains. The reason for this is not clear, but it may be due to the ration conditioning that occurs with wet distillers' grains. There are some questions about our ability to accurately measure the dry matter content of wet distillers' grains, as it has been suggested that some volatile compounds may be "dried off" when we use conventional oven drying methods. This concept can get a little complicated and may be more important from an academic standpoint because the most relevant dry matter determination method is the one that the ethanol plant uses. In other words, the dry matter that you pay for is the most important value. Whatever method is used to determine the dry matter content of distillers' grains, variation in the dry matter content from load to load needs to be monitored. As stated above, the nutrients and energy that the cattle need are contained in the dry matter portion of the distillers' grains and therefore a load with a greater dry matter content is worth more on an as fed basis than a load with a lower dry matter content. For example, a ton of as fed distillers' grains with a dry matter content of 35% contains 700 pounds of dry matter, whereas a ton of as fed distillers' grains with a dry matter content of 32% only contains 640 pounds of dry matter. Therefore, the load with a dry matter content of 32% is worth about 8.6% less on an as fed basis than the load with a dry matter content of 35% (assuming the nutrient profile is the same).