Pros and Cons of Distillers’ Grains
Distillers’ grains offer ration benefits, but be aware of sulfur levels.
With winter just around the corner, it’s time to start thinking about protein and energy supplementation again. There are many advantages to supplementing your winter feeding program with distillers’ grains or products made with distillers’ grains. However, there are also some disadvantages that need to be considered before feeding decisions are made.
Advantages of feeding distillers’ grains
Corn used for ethanol production goes through a process of fermentation in which the starch is removed from the grain. Remaining nutrients, such as protein and fat, are concentrated to approximately three times the level found in corn grain itself. Distillers’ grain contains between 25% and 35% crude protein (CP), making it a good winter feeding source of this critical nutrient.
Distillers’ grains are typically included in the diets as a source of protein; however, it has an energy value equal to or greater than corn. With the removal of starch from the grain, the energy comes from corn oil and digestible fiber, as well as some from crude protein. Due to the energy in distillers’ grains coming primarily from digestible fiber rather than starch, it is less likely to upset the rumen and create acidosis compared to corn.
Distillers’ grains are also a good source of phosphorus and can reduce or eliminate the need for phosphorus supplementation. It is still important for producers to have balanced mineral programs in place to maintain a minimum calcium-to-phosphorus ratio of 2:1.
Disadvantages of feeding distillers’ grains
The nutrient composition of distillers’ grains can be variable due to differences in the processes within ethanol plants over time, as well as differences in production between ethanol plants. In addition, solubles are added back to distillers’ grains in differing proportions, which further increases nutrient variability.
Sulfur levels in distillers’ grains range from 0.35% to 1.4%, which can potentially cause health concerns in beef cattle. Cattle have a nutrient requirement for sulfur of 0.15% dry matter — with a maximum tolerable threshold of 0.4% (Nutrient Requirement of Beef Cattle, 2016).
Clinical signs of sulfur toxicity include decreased feed intake and slow or stunted growth. Sulfur toxicity can also contribute to the incidence of polioencephalomalacia. In addition, high sulfur concentrations can lead to decreased copper absorption and the potential for copper deficiency if proper mineral supplementation is not available.
It is extremely important for producers to consider all of the sulfur sources that will be consumed by cattle before deciding to include distillers’ grains or related products in winter feeding programs. Sources containing sulfur include all feedstuffs, supplements and water. Water sulfate levels of 1,000 parts per million (ppm) or less are considered safe and may be a diminished cause of concern when feeding distillers’ grains; however, many western ranches see water sulfate levels reaching 3,000 ppm or higher. In high-sulfate areas such as these, distillers’ grains should either be fed with extreme caution or not at all.
It is very important that samples be taken of water, distillers’ grains or related products, and all feedstuffs to ensure cattle health. In areas where sulfate levels can be high, distillers’ grains should be routinely tested to ensure total dietary sulfur remains below 0.4% of the dry matter and water source combined.
Ranches with high molybdenum in forages also pose a risk to cattle when distillers’ grains are fed. In addition to high sulfur often found in distillers’ grains, high molybdenum in forages can also bind copper and prevent absorption, posing an even higher risk of copper deficiency when combined with feeding distillers’ grains.
Editor’s note: Cadra Van Bibber-Krueger is a beef nutritionist with Hubbard Feeds. Photo by Kasey Brown.
