By Ruth Correll
Soybean harvest in Wilson County was hit and miss this fall. Rainy weather prevented timely harvest. Some beans remain in the field and may not make the grade at grain elevators when harvested.
This leaves the dilemma of what to do with these beans to try and recover some of the costs of production. There is potential for feeding these beans to beef cattle but certain precautions should be followed.
Whole soybeans are usually processed by cooking. Unprocessed soybeans have several enzymes that can make them potentially a risk. Whole raw soybeans should never be fed to monogastrics such as horses and swine or young calves less than 300 pounds.
One of the risks is raw soybeans contain urease. Urease breaks urea down into ammonia. Do not feed any combination of urea-containing products with whole raw soybeans. When urease in soybeans is fed with commercially available protein tubs and blocks containing urea, the increased activity of urease in raw soybeans can result in a more rapid breakdown of urea into ammonia within the rumen potentially leading to ammonia toxicity and cattle death. Be aware of all ingredients in feeds provided to cattle if feeding raw soybeans.
Whole soybeans can be effectively used as protein supplements for beef cattle, but feeding guidelines must be followed. Raw whole soybeans normally have about 40 percent crude protein and 20 percent fat. Due to the high fat content, whole soybeans should be limit fed so the total dietary fat level does not exceed 6 percent for mature cattle or 4 percent for growing cattle. High fat levels can lead to reduced digestibility of forages and other feedstuffs. Grazing soybean stubble containing whole beans has risks and is not recommended. Overconsumption cannot be monitored if grazing.
If considering grinding raw soybeans, be aware grinding decreases their shelf life. Feed ground soybeans within three weeks following processing and sooner during humid conditions.
Late harvested soybeans have the potential for high quantities of mold. Mold does not have to be visible for mycotoxins to be present. In addition to obtaining a feed nutrient analysis, have an aflatoxin-screening test done prior to feeding. Calves are more susceptible to aflatoxicosis than mature cattle.
Bottom line . . . raw whole soybeans can be successfully used in beef cattle diets only if precautions are taken and producers know the risks. Do not allow young calves to consume raw soybeans, and limit feed quantities of whole soybeans to mature cattle. If grinding raw soybeans, feed within three weeks of processing.