Increasing corn prices and dropping milk prices are causing dairy producers to think twice about what they feed their cows this spring.

“Dairy farmers can’t afford to take cows off feed now because it takes too long to bring them back into full production,” says Mike Hutjens, University of Illinois professor of animal sciences emeritus. “The good news is that dairy cattle have an advantage because they can utilize forages and byproduct feeds. The bad news is that the price of corn increases the price of alternatives as well.”

Alternative feedstuffs such as distillers grains, corn gluten, fuzzy cottonseed and alfalfa hay may not be corn, but they’re all in the same market, Hutjens adds. As nutrient prices go up in starch and energy, it drives the other prices up as well.

“Producers need to look at how much corn they should be feeding,” Hutjens says. “For a dairy cow, 24-26% starch is the typical level. Producers can get that from hominy, corn silage or shelled corn. So the question becomes what are the more economical sources available at the farm?”

As prices go up, sugar becomes an alternative that can feed rumen bacteria (target 4-6 % of the total ration dry matter). Another source is soluble fiber, or fiber that the rumen microbes can break down in the rumen (target 10-12% of the total ration dry matter).

“The bottom line that our producers need to realize is that you can’t cheat the bacteria; they don’t read the farm magazines and know the price of corn went up to $7.60. They just know they need certain carbon structures in the rumen to produce. We never want to slow them down. As a result, they produce 80% of the cow’s energy and 60% of her amino acids. Make sure rumen microbes are maxed out even if the price of corn appears to be high.”

Corn is still a good buy, Hutjens says. Sesame, a software program developed by The Ohio State University, evaluates 30 feedstuffs in the Midwest. It compares energy, protein forms and fiber sources to come up with a commonality that says what the feedstuff is worth.

“Believe it or not, corn is underpriced,” he says. “We can afford to pay more than we are now when you look at all the other energy sources available. We can pay over $8/bu and it’s still a better buy than looking at most alternative feedstuffs, with the exception of corn silage and distillers grains.”

Corn distillers grains need to be on the radar screen for dairy producers along with corn gluten feed. Both are underpriced at this point. In fact, distillers grains are underpriced by nearly $100/ton.

“The big question producers want answered is how much distillers grain can they feed,” he says. “I typically advise 5 lbs of distillers grains dry matter per cow per day. It ends up being about 10% of the ration, and that prices out very economically.”

While the price of corn is projected to remain very high through the summer months, the price of milk is projected to fall through the end of the calendar year. Hutjens suggests using Sesame to find the breakeven price at full feed.

“High-producing cows fed correctly will make money in 2011 with $7-plus corn,” he says.