More dairy nutritionists and producers are making do with less alfalfa in their cows’ diets this year.
Several factors are forcing dairy producers, particularly in the Midwest, to find other ways to provide their animals with needed effective fiber.
“Drought hit some parts of Wisconsin pretty heavily last year – a drought that was nationwide to some degree, bringing low forage inventories coming into spring for many,” says Randy Shaver, University of Wisconsin Extension dairy scientist. Then winterkill took about 1.75 million alfalfa acres out of production in Wisconsin and Minnesota alone, according to National Agricultural Statistics Service data.
“We followed that with conditions that didn’t allow us to get corn in the ground for long periods of time in some dairy areas in Wisconsin – and high hay prices. We had a real (forage) shortage nationally for a number of different reasons,” he says.
Many Midwestern dairy cows this year won’t be fed the typical total mixed ration (TMR) that includes 16 lbs of alfalfa, says Noah Litherland, University of Minnesota Extension dairy nutritionist.
“We’re going to be seeing some interesting diets. People are going to be branching out more than they have in the past. Some diets are going to be having more byproducts. They’re going to be looking more at that soluble fiber number that comes in a forage analysis and how that blends with the effective fiber that we have,” he says.
Shaver predicts rations in his state will show higher amounts of corn silage. That’s in part because a lot of winterkilled alfalfa ground was planted to corn, and late-planted grain corn may end up harvested for silage.
A number of producers and custom harvesters are outfitting their choppers with Shredlage processors, using a new method of harvesting “that typically will allow people to chop a bit longer and get more effective fiber out of corn silage,” he says. The silage processed through Shredlage rolls is cut at a particle length of 26 mm rather than the 19 mm advised for conventionally processed corn silage (see “Shredlage Takes Hay From Dairy Diets”).
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Illinois growers contended with a rainy, wet spring, says Mike Hutjens, University of Illinois emeritus Extension dairy nutritionist. Hay acres that traditionally produce 150-160 relative feed value alfalfa turned out 120-130 RFV feed. “It’s a lower-quality forage that is a little trickier in terms of building a balanced ration.”
He and Shaver estimate that more farmers will be feeding “fresh corn silage” or silage that’s had only a few weeks of fermentation.
“In some cases, we will see some more digestive upsets and we will lose some milk production, because cows don’t handle it as efficiently as fermented corn silage,” Hutjens says.
“There isn’t a lot of carryover corn silage,” Shaver adds, “so we don’t have that forgiving factor of letting it sit in the silo for six months or eight months to allow that starch digestibility to increase.”
A lot of alternative forages, including winter wheat, winter rye, oats and oat-pea mixes, were harvested as spring silage, Shaver says. Early cut forage came off with “fairly low nutrient detergent fiber (NDF) and high protein and can be a fairly good substitute for alfalfa silage. On the other hand, if you couldn’t get it off due to rain, and it was late-cut, you pretty much had to divert that to heifers and dry cows.”
Studies on oats and other small grains have shown quality declines as the forages mature, he adds. “Some of the alternative forage material can be pretty good quality and some of it, not so good.”
That means taking forage tests frequently at feedout is “critical,” Shaver says.
Straw, a “pretty low-quality forage,” can provide effective fiber, Hutjens says. “A pound of straw could keep a TMR pretty honest.” Cornstalks are another option, although they bring soil contamination to a diet, he says.
“Certainly cornstalks, if we can get them harvested and processed or put into a bag as stalklage, can be good feed for heifers or dry cows or even to displace some of that wheat straw that people are shipping in from out West,” Shaver says.
High-fiber byproducts, whose prices track with corn and soybean meal prices, are becoming affordable again as alfalfa replacements, says Shaver. “With some of these, we may be able to reduce forage needs by about a third. Cottonseed hulls or whole cottonseed have a pretty good fiber replacement value. If feeding 5 lbs, you might displace 5 lbs or more forage dry matter per cow per day.
“But others, such as brewers grains or corn gluten feed, if you feed 5 lbs, you would only be able to displace about 2 lbs of forage. Distillers, brewers and corn gluten feeds are very finely processed.”
The two dairy scientists recommend the use of a program that tracks feed values, such as Wisconsin’s FeedVal 2012 and Ohio State’s Sesame.
Producers should constantly monitor their forage inventories and work to rebuild them with fall plantings, possibly also buying silage corn acres, Shaver says.
“A lot of things can happen between now and the end of the year in terms of building back inventory next spring,” he says. “It wasn’t a good place to be with silos running empty and alfalfa fields that didn’t green up. So I would think a little bit ahead about how we can get ourselves out of that.
“There is still a drought going on in the Southwest, and there’s a big demand for hay nationally. So I think we’ve got to build back some of our own inventory in the Midwest.”
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