Soybean Meal - They're Not All the Same

Dr. Maurice Eastridge, Extension Dairy Specialist, The Ohio State University

Soybean production is among the top for cash receipts for agricultural commodities in Ohio. In 2006, soybeans ($1.4 billion) ranked second to corn ($1.6 billion) for cash receipts. However, during this same time period, 1.5 more acres of soybeans were planted in Ohio than acres of corn. With the demand for corn to use in ethanol production, the balance between acreage of soybeans versus corn in Ohio has been titling more toward increasing production of corn, yet soybean production remains high. Right behind corn and soybeans relative to agricultural cash receipts in Ohio is dairy and poultry. Although we’re not just using a local, in-state market for soybean based products, the dairy and poultry industries in Ohio utilize a lot of the soybean meal (SBM) as a valuable animal feed. The value of this relationship between the crop and animal industries in the State is vital. If you haven’t noticed, the Ohio and American Soybean Associations have been advertised heavily during recent months the importance of the livestock industry to the market for soybean products.

Soybeans contain about 40% protein and 20% fat [dry matter (DM) basis]. Soybean meal has been a staple in animal diets for many years, to the extent that it is often not even viewed as a by-product from the oil extraction process. The “vegetable” oils that you purchase in the local grocery store are primarily soybean oil. The oil is primarily removed through a solvent extraction process, and this is very through in removing most all of the fat (about 1.5 to 3.0 % fat remains). The hull of the seed is removed, the seed is ground or flaked, the solvent hexane is used to extract the fat (hexane is then removed from the fat), and the meal is ground for uniform particle size. If the hulls remain separated (sold as a separate commodity), then the meal contains about 48% crude protein (about 54% CP, DM basis), but if the hulls are added to the meal, then the meal contains about 44% CP (about 50%, DM basis). These two feeds are readily available on the market. The protein in SBM is of high quality (based on amino acid profile), but much of this is degraded in the rumen compartment of ruminants. Increasing the supply of this high quality protein to the small intestine for digestion and absorption is worthwhile, and one of the ways to accomplish this is by heat processing of the SBM. Mechanically extracted SBM results whereby soybeans are reduced in particle size and exposed to extreme pressure to remove the fat. This process differs from solvent extraction in that more heat is generated, thus more of the protein becomes what we refer to as rumen undegradable protein (RUP), and less fat is removed (6 to 10% fat may remain depending on the processor).

Because of the value of RUP, mechanically extracted SBM may be worth 60% more than 44% CP SBM or 40% more than 48% CP SBM. The mechanically extracted SBM also contains more fat than solvent-extracted SBM which adds energy value to the feed. Why is this discussion so important at this time? There are two reasons: 1) with the increase in biodiesel production, more soybean oil is being extracted by mechanical extraction, even by small processors, and 2) with the high feed prices caused by the corn market for ethanol production, purchasing feed ingredients based on nutrient provided and costs is extremely important to farm profitability, especially when you consider that feed costs contribute more to the cost of food animal production than other variables. Some commercial sources of high RUP SBM are available, and some biodiesel producers are making efforts to market the resulting mechanically extracted SBM as a premium product. Some general considerations for purchasing such SBM sources are:

  1. Although some heat application is good for increasing RUP, overheating during processing can reduce digestibility of protein in the small intestine. The SBM product should be deep yellow to light brown in color as a visual indicator for extent of heating.
  2. Considerable variation can occur within a plant/facility on the efficiency of the extraction process, resulting in a variable amount of heat applied and amount of fat removed. For example, the amount of fat in mechanically extracted SBM in about 3 to 4 times more variable than in solvent-extracted SBM. So putting it in context, if you are purchasing the product based on relative high RUP and fat and the concentrations drop, then you are being over-priced for the feed. Assuring consistency of the product by the processor is very important to you as a buyer.
  3. Some of the biodiesel producers are still refining their process, yet they have “product”, and some are quite small for the amount of SBM that they can provide relative to your needs. So your market can be quite valuable to them because you should be looking for a consistent supply of a high-quality product. Disruption in either of these two principles (supply and quality) means risk for you that must not be overlooked in pricing of the product by the processor. You are likely to be financially ahead by contracting SBM needs for a year from a large supplier than making intermittent purchases from a small processor and buying additional SBM on a non-contract basis from a large processor.
  4. Current value of the SBM should be compared relative to the availability of other feeds based on nutrient profile and price (see price comparisons elsewhere in this newsletter in the article titled "Cost of Nutrients and Benchmarks of Profitability for Ohio Dairy Farms". All too often, feeding decisions are based on always feeding a certain commodity rather than from the approach of meeting the nutrient needs of the animals using more economically-price ingredients.

The SBM will remain an important feed ingredient for animal agriculture, and with the fuel production processes underway using oils and starch, some additional (new suppliers and increased amounts) protein feeds will be available to livestock producers.