Illini BeefNet Papers
Soybean prices are at their lowest level in 25 years because of large worldwide soybean production. Cattle producers might be able to economically feed ground raw soybeans to beef cattle. Generally, if the cost of soybeans is below 94% the cost of soybean meal (SBM), they can economically be included in beef diets to replace soybean meal. Today's percentage difference is about 92% indicating that soybeans will be an economical replacement for soybean meal in growing and finishing diets. They can also be used as a source of supplemental protein and fat in beef cow diets.
Raw soybeans are lower in crude protein and ruminal undegradable protein than SBM, but have higher fat content. Heat treatment like extruding increases ruminal protein escape and improve overall digestibility of fatty acids, but it is probably not economical give the high cost of processing. The heat processing will break down the trypsin inhibitor, but this is not a factor for cattle.
The beans should be coarsely crushed for maximum performance. They can be fed whole with some reduction in performance. The level of reduction will depend upon the type of diet and feeding conditions. If you process the beans, they may gum up rollers or grinders of they are not mixed with other grains. They should be fed within one week of crushing in hot weather or two weeks of crushing in cold weather. They should also be introduced gradually into the diet to prevent diarrhea and reduced performance.
In feedlot diets, research has shown that soybeans can be fed up to 24% of the diet without influencing animal gain or feed efficiency. There is a tendency for feed intake and daily gain to decrease with increasing level of soybeans. I would recommend a maximum level of 15% of the diet dry matter (about 3 lbs) of soybeans for feedlot cattle. Some data from Iowa State University suggests that feeding soybeans decreases feed intake and increases feed efficiency relative to SBM or urea. They also observed that feeding soybeans increased the level of polyunsaturated fats in blood, subcutaneous fat, and intermuscular fat. This might provide some health benefit for meat from cattle fed whole soybeans.
Missouri work has suggested that feeding soybeans will increase first service conception rate by about 10 percentage units. This improvement may be due to supplemental energy (from the fat) or supplemental protein. The improved fertility may also be a function of specific long chain fatty acids (like linoleic acid) found in soybeans. These fatty acids inhibit the production or release of prostaglandin thus increasing the chance of embryo survival. The maximum levels of soybeans are similar to those fed in feedlot situations, but the desired improvement might be available at 1-2 lbs of soybeans.
Soybeans offer an opportunity for beef producers in Illinois to lower their feed costs and improve profitability provided they have the equipment and facilities to feed the soybeans.