If you're in the market for a new hay cutting machine, here's a crash course from Dan Undersander, University of Wisconsin extension forage specialist, taken from his presentation at the National Alfalfa Symposium in early February. He discussed the available conditioning options and also talked about wide swaths, other haying equipment and ways to reduce ash content in forages.

"There are two major types of conditioners," he explained. One is a flail/impeller and the other uses rubber/steel rolls. "The big argument is over which is better. The impeller creates a stripping action; the rubber rolls create a crushing action. The impeller tends to have higher leaf losses and the roll may leave strips in the field if you have light crops."

Flails/impellers are "definitely better for grasses," he said. But for alfalfa, he would vote for conditioners with rubber rolls. Research shows that flail conditioners lose 2-4% more alfalfa dry matter than conditioners with rubber or steel rolls, Undersander said.

"But whether it's a flail or a roller, it's the adjustments that are so crucial. I've seen time and again where machines came from the dealer that had not been adjusted as they should have been. You should really take charge of that yourself and pay attention to it," he warned. Adjusting the amount of tension will depend on the amount of hay going through "and you will need to adjust that for each field."

The spacing of the rollers is another area that needs attention, he said. "Generally, the spacing should be about the thickness of a quarter. The easiest way to check that is to go into your kitchen and take a sheet of aluminum foil and roll it up into an inch roll. Then feed it through your mower-conditioner's rollers.

"Now, my safety people tell me I need to remind you to shut the mower off first," he said. "Then you put that roll through and look for thin spots (where clearance is more or less than a quarter)."

"We find that the real difference (between the two types of conditioners) is in the adjustments, the management of the machines. So either can do a good job in terms of drying rate."

For "more severe" conditioning, growers may want to research superconditioners or macerators, Undersander said. "The difference between the superconditioner and a regular conditioner is that the superconditioner completely crushes the alfalfa stems instead of simply breaking them in a few places." Superconditioners don't strip off the leaves, either.

"They really do work, but you have to decide how much you need that extra drying time. There have been numerous trials of these products and the superconditioner always did dry a little bit faster. In a day it made about seven to eight points of dry matter difference, so we're seeing maybe three to five hours difference in drying rate." Superconditioners can cost $15,000-20,000 more than regular conditioners, he added.

Macerators fracture hay stems, Undersander said. Hay is crushed first by two rotating rubber rollers, then by a set of steel serrated rollers, rotating at a slightly different speed. "In addition to smashing the whole stems, it just scrapes off the wax, really enhancing the drying rate." Developed at the U.S. Dairy Forage Research Center, Madison, WI, the macerator is being marketed by a Canadian company.

"The original model could pretty much get alfalfa hay dry in the Midwest in a day for haying. The challenge was, it was a very slow process. With the macerator that is on the market, we still have the problem that it is slower than our mowing and conditioning although we speeded up the haymaking by macerating less. The unit on the market does work, it's just important to remember that it doesn't macerate as much as the pilot unit did.

"It is an expensive unit, and we need to decide if we really need that three or four or five or six hours in terms of increased drying time over conditioning."

Read the recap of Undersander’s entire presentation, entitled: What's New In Forage Equipment: Manipulating Hay Swath To Speed Drying.