Answer by Dr. Bill Weiss, dairy nutrition specialist, Ohio State University
Q: Corn and soybean meal have been staples in our feeding program, but with today’s prices what are some of the alternatives?
A: An important nutritional concept to remember is that cows do not require specific feeds — they require nutrients.
When considering potential alternatives to corn and soybean meal, you need to think about what nutrients those feeds provide and whether combinations of other ingredients can provide those nutrients at a lower cost.
For major ingredients (not mineral/vitamin supplements), the nutrients that make up the bulk of their economic value are net energy (NEL), rumen degradable protein (RDP), digestible rumen undegradable protein (dRUP), and effective fiber (eNDF). Non-effective NDF (nNDF) is not a nutrient, but it affects the cost of feed ingredients because it is not a good source of digestible energy for non-ruminants (poultry and swine), but can provide energy to ruminants. The concentrations of specific undegradable, digestible amino acids can be used in place of dRUP, but for simplicity I’ll just use dRUP.
In December, 2007 in central Ohio, NEL was worth about 0.14 $/Mcal; RDP was worth -0.2 $/lb; dRUP was worth 0.35 $/lb; eNDF was worth 0.07 $/lb, and nNDF was worth -0.06 $/lb. Negative values for nNDF and RDP indicate that demand for feeds that contain substantial amounts of the nutrients is relatively low, so they are being discounted by the feed markets.
If you take the nutrient economic values and multiply them by the amount of each nutrient in 1 ton of feed, and sum the values, you obtain an estimate of the break-even price of the feed ($/ton). If you can purchase that feed for less money, it is a bargain; if the feed cost more, then it is overpriced.
Because the calculations to estimate the cost of nutrients are extremely complex, a computer program is available (SESAME). An alternative is to go to the Buckeye Dairy Newsletter, find the most recent edition and read the article on "Cost of Nutrients." That article will contain a table with a list of common feeds that are "bargains," "breakeven-priced," or "overpriced" based on prices in central Ohio (this table is probably appropriate for much of the Corn Belt).
In December, 2007, corn grain was a "bargain." That doesn’t mean corn is cheap; it means that corn provides nutrients at a lower cost than what the nutrients are currently worth. Conversely, soybean meal is overpriced; its price exceeds the value of its nutrients in the current market. Cottonseed meal, expeller soybean meal, and distillers grain are bargain-priced and could be viable alternatives to soybean meal.
Some people might question how it can be that soybean meal is overpriced, while expeller soybean meal is a bargain, when a ton of expeller meal costs more than a ton of soybean meal. The reason for this is that a ton of expeller meal provides more dRUP (an extremely expensive nutrient) and more NEL (currently at historically high price) than regular soybean meal, so it is worth more. The difference in price between expeller meal and regular soybean meal is less than the difference in the value of its nutrients.
A few words of caution:
- Local market conditions can greatly influence cost of some feeds (for example, wet distillers grain will be very cheap if your farm is next to an ethanol plant). SESAME will give more accurate values if you use local prices rather than the values calculated for central Ohio.
- SESAME does not consider "non-nutrient value." A load of cottonseed contaminated with aflatoxin might be a good value based on SESAME, but it actually is worth nothing.
- Constantly changing ingredients in the diets can reduce milk production. Look for longer-term trends in the feed market rather than changing ingredients every time the price changes. For example, distillers grains are likely to be bargain-priced for a long time (but maybe not every single week), so you might want to consider them.