– Jason Hartschuh, Extension Field Specialist, Dairy Management and Precision Livestock, Ohio State University Extension and Garth Ruff, Field Specialist Beef Cattle and Livestock Marketing, OSU Extension
Some elevators have rejected badly damaged soybeans.
The storm damage from Hurricane Helene to soybeans has caused reports of $6 per bushel discounts due to sprouting and off-color damage. We have received a few questions about feeding these soybeans to livestock. For now, we will have to generalize the nutritional value and risks based on information from past experiences in other regions of the country, but we have submitted soybeans for feed testing.
If you plan to feed whole damaged soybeans to your livestock a complete feed analysis is needed that includes a fat content analysis, mold, and mycotoxin test. While expensive, a full mycotoxin panel should be run because soybeans can contain many toxins including ZEN, FUM, DON, and Aflatoxins.
Damaged and discolored soybeans make a good protein source for cows and can be used in heifer development rations along with growing and finishing diets. Ruminants can be fed raw or roasted soybeans however, raw soybeans contain a trypsin-inhibiting enzyme that is important to protein digestion in non-ruminates. Nursing calves under 300 pounds should not be fed raw soybeans. Roasting soybeans kills some molds, inactivates trypsin, and increases protein absorption while creating a rumen-undegraded protein that is absorbed in the intestine of cattle.
Feeding raw soybeans to growing cattle may result in decreased gains compared to distillers grains when used in a forage-based diet. Roasting soybeans can improve performance compared to feeding raw soybeans. Urea should not be used in rations in which raw soybeans are being used. Raw soybeans contain urease that can rapidly turn urea into ammonia and cause ammonia toxicity.
Raw soybeans contain approximately 40% crude protein and 20% fat. When transitioning cattle to raw soybeans from other protein sources it should be done gradually over 14 days. The high fat content in soybeans can negatively impact fiber digestion. Soybean inclusion rates should not exceed the animal’s protein requirements. In growing calves, soybean inclusion rates should be limited to 7% of the diet or less and 5% of the diet or less in finishing diets. Total supplemental fat from soybeans or other sources in a feedlot diet should not exceed 10% with 7.6% of the diet a safer amount in most rations.
Corn and corn byproducts also contain fat that needs to be included in the total ration fat. For mature cows soybeans should not be fed at more than 10% of the diet on a matter basis or approximately 2-3 pounds daily. Grinding raw soybeans can improve their digestibility but also exposes the fat inside them to the elements which can cause it to become rancid. If grinding raw soybeans, they should be fed within 3 weeks, especially in warm humid weather.
Raw soybean protein is approximately 70% rumen degradable and 30% rumen undegradable. Growing calves on a corn silage diets or other diets low in rumen undegradable protein have greater rates of gain when distillers grain or other protein sources high in rumen undegradable protein are utilized. Cattle fed raw soybeans as a protein source to supplement corn silage may experience lower rates of gain compared to protein sources that are high in rumen undegradable protein.
If retaining sprouted soybeans as livestock feed, bin management to prevent molding will be critical. During harvest sprouted soybeans often break apart with many pieces leaving the combine. Pieces that remain in the harvested grain can promote spoilage due to the breakdown of carbohydrates, proteins, and fats in the seed that is initiated during the germination process. Current weather conditions have redried soybeans but if they get wet again or have high moisture areas in the field they should be dried down to 11% moisture to inhibit fungal growth, aerated in storage, and regularly inspected in the bin.
Poor-condition grain storage is risky. Utilizing technology like temperature monitoring cables can allow for better monitoring of the risk of spoilage in your soybeans.
Next week we hope to provide an update on the nutrient value and mycotoxin risk of a couple of samples of sprouted and damaged soybeans. Before using them as a protein source for your livestock you should test your soybeans and consult with a nutritionist about the inclusion rate in your ration.