Alkaline treatment of corn stover: Can it work on my dairy?
Posted on October 10, 2012 in Dairy Performance
By John Brantsen and Jon Urness As we’re looking to make the most out of our crops this year, alkaline treatment of corn stover is gaining attention as a potential strategy to improve the feed value of this byproduct. Research shows that treating feedstuffs with calcium oxide increases cellulose digestibility, which improves the feed value of byproducts like stover and straw. Recent work from the University of Wisconsin suggests that NDFD may increase by as much as 10 percentage points. The process The critical first step in the alkaline treatment process is adding water to reach 50 percent moisture. Add calcium oxide at 5 percent or calcium hydroxide at 7 percent of the feedstuff dry matter. For example, a ton of 70-percent DM stover (1,400 pounds DM) would need 800 pounds of water (100 gallons) added to yield a mixture with 50 percent moisture. The alkaline treatment requirement for such a mixture would be 70 pounds of calcium oxide or 98 pounds of calcium hydroxide. This process can be slow and tedious. Thorough mixing and adequate processing of the material is essential. Tub grinders are most commonly used to process the stover. It’s then moved to a mixing wagon where the water and alkali material can be added during mixing, which may require 15 to 20 minutes. Storing the feed The chemical reaction that breaks down the cellulose takes at least one week, so you should not feed the stover prior to that timeframe. Treated stover can be stored successfully for longer periods of time, but packing and quality plastic covering that is weighted down is essential to exclude oxygen and limit mold growth. Feeding, performance and economics A University of Nebraska trial with yearling feedlot cattle reduced dry corn from 46 percent of the diet to 36 percent by adding 20 percent of the diet as alkaline-treated corn stover and removing 10 percent of the diet roughage. Doing so did not sacrifice performance or carcass yield. Application for dairy rations is generally untested. To determine whether this is an economical option, you need to calculate the cost of the alkali material ($300 to $350 per ton) plus the cost of the stover, grinding and labor. Weigh that against an equivalent source of corn, such as corn silage. The economics demonstrated in the Nebraska trial, coupled with the need for an emergency source of forage, may favor this process rather quickly. Again, very little is known about this feed in dairy rations. Feedlots are replacing up to 50 percent of the corn silage in very high concentrate diets. The amount used in dairy rations should probably be less. Safe handling Calcium oxide can be very caustic and blisters and skin irritation have been associated with handling this material. The process also involves a fair amount of dust that should not be breathed in or come in contact with skin. In addition, these materials are very difficult to clean from equipment. Finally, the chemical reaction generates a lot of heat and temperatures will rise as high as 190°F. Adequate moisture is essential for the process to work and avoid ignition. Fires have been known to occur. Further information Click here for a Vita Plus technical bulletin on this topic. Click here for information on alkali treatment of corn stover from the University of Nebraska. Scroll down to the presentation on “Alkaline Treatment of Forages.” About the authors: John Brantsen is a dairy specialist with the western region dairy team and based in northwest Iowa. He earned a bachelor’s degree in animal science from Iowa State University. He previously worked at Trans Ova Genetics in Sioux Center, Iowa, first as an embryologist and lab manager and then as the calving department manager. In his time, the calving program grew from 20 to 150 bottle calves per month. Brantsen also serves as a volunteer EMT for the Sioux Center Ambulance Service and he and his wife coach the local youth tee-ball program. Jon Urness is the Vita Plus national forage specialist. He grew up on his family’s five-generation homestead dairy near Black Earth, Wis. and still lives there today. He graduated from the University of Wisconsin-Madison in 1977 with a bachelor’s degree in agricultural journalism. Since 1992, Urness has provided on-farm dairy nutrition consulting in southwest Wisconsin as a Vita Plus employee owner. He has also taken on the forage marketing responsibilities outside of the traditional Vita Plus market.
Forage storage and management