Using a vertical auger mixer just wasn’t delivering the total mixed ration Andrew Kuehnert and his family wanted for their Midwestern dairy.

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Too often the ration was undesirably dense, comprised of overprocessed soft forages, such as silage and haylage, and underprocessed stiff fibers, such as hay and straw.

“Making an unsortable feed is what we were looking for,” Kuehnert says. “I wanted my refusals to look like the feed I put out the day before.”

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Two years ago, Kuehnert switched to a horizontal drum mixer with rubber paddles and cutting knives and has since seen an increase in mix consistency and rumen health.


After seeing the dairy struggle to consistently produce a ration difficult to sort, the dairy’s nutritionist Rich Nisen recommended that it switch to a new mixer manufactured by Keenan and promoted through Nisen’s employer, ADM Alliance Nutrition.

“The technology the Kuehnerts are now using tells them the mix order, the amount of time each ingredient needs to mix individually in sequence and then together in the end.

So every mix should be extremely uniform for each batch, irrelevant of who did the mixing,” Nisen says.

Working with stiffer forages can be difficult in vertical mixers, Nisen says. They will often not chop these forages thoroughly and tear or shred forages, whereas the Kuehnerts’ new mixer is chopping forage to consistent length with clean-cut ends.

“We wanted to do anything that was possible to maximize the use of homegrown feeds in the ration,” Nisen says. “With the way the mixer’s knives are set up and its gentle tumbling action, we’re getting a cleaner cut while not overprocessing our soft fibers.”

The Kuehnerts’ 285-cow registered Holstein dairy is within a football field’s distance of the Fort Wayne, Indiana, city limits. Andrew and his brother, Nathan, represent the fifth generation of ownership for the 125-year-old dairy. For years, encroachment from the city has limited the dairy’s land base for growing its own feed.

The Kuehnert family farms 300 acres and cash-rents another 600 acres, all of it going into forage production. With land selling for $10,000 to $12,000 per acre, they never know from year to year just how much land they will be able to farm.

“We wish we owned more but we just can’t afford it,” Kuehnert says.

Last year was the first year the dairy chopped and processed its own forages. It was a rough year for yields with silage producing about 10 to 20 bushels per acre and tonnage was half of what is normally expected. The dairy has had to purchase 20 percent of its total silage usage this year.

Last year’s poor yields have also limited the forage inclusion in this year’s ration. Kuehnert hopes a more plentiful silage harvest will allow him to move the ration’s forage dry matter percent from 30 percent into the upper 50th percentile.

He believes higher-quality forages and more of them will enhance the improvements provided by the new mixer.

“We’ve been able to see the real, true benefits of higher digestible forages because of our new mixer,” Kuehnert says.

Feeding for consistency

The main benefit of the new mixer, Kuehnert says, is consistency in mixing and delivery of feed. The dairy employs multiple feeders who mix rations, so providing consistent feed had been a challenge.

“It seemed like we were throwing the cows for a loop over time,” Kuehnert says.

The tell-tale sign something was amiss was pieces of forage that were too long consistently showing up in the diet.

“It seemed we would always be getting some long pieces of fiber in there and the cows would be able to sort that out,” Kuehnert says.

Nisen says mixing equipment plays an important role in ration particle length. Vertical mixers can get stiff fibers to within the optimum feed length of one to three inches; however, he says that it often requires pre-mixing these ingredients separately, adding man-hours and the risk of shrink to the process.

Without pre-mixing, chopping stiff feeds to optimum length in a total mixed ration usually leads to “pulverizing” corn silage and a ration that is too dense, he says. Such was the case on Kuehnert’s dairy before switching equipment.

Now, just as advertised, Kuehnert says his new mixer generates feed that’s as fluffy as a bird’s nest. Nisen says that can be attributed to the mixer’s variable settings for cutting stiff fiber feeds, which are rated on a scale of 1 to 5.

The mixer accounts for differences in forage thickness, from a dry, brittle fourth cutting of hay to a waxy, damp first cutting, Nisen says. It adjusts the number of mixing revolutions accordingly.

“The mixer’s rubber paddles sweep feed past the cutting knives, and with a gentle tumbling of only six to eight revolutions per minute, it’s hard to overprocess feed,” Nisen says.

What’s most different about preparing the Kuehnerts’ ration is the mixing order. With their new mixer, they add the liquid portions of the diet – water and molasses – first and then forages last.

Kuehnert says the new mixing order means a more even distribution of the liquid nutrients.

“With our old vertical mixer, you’d throw everything in and then you’d have to let it grind while you put the water in at the end. Even then you’d be dumping the liquid toward the back half of the mixer,” Kuehnert says.

Nisen likes how the new mixer distributes the feed too.

“The feed in this mixer never touches an auger until feedout,” Nisen says. “You don’t get constipated feedout like you do with other mixers. It pulls the feed from the front and the back with an auger that empties at the center of the wagon.”

The new mixer is so far achieving Kuehnert’s goal of feeding an unsortable ration.

“Since getting the new mixer, we’ve really eliminated sorting,” Kuehnert says.

The added health benefits

Consistency in mixing and delivery has led to rumen health and production benefits. Reduced sorting and more optimum fiber length has slowed the passage rate of the diet through the rumen, Nisen says. This has improved milk components and reduced dry matter intake (DMI) by nearly a pound.

But the mixer has done other things beyond just improving components and efficiency, Kuehnert says.

The most noticeable health improvement the dairy has seen is in the transition and fresh cow groups.

“We’ve been able to provide a fair bit of fiber but still keep the ration’s energy density up,” Nisen says. “We’ve been able to bump up high-moisture corn inclusion and push the cows a bit harder because the chance of sorting is less and the cows are healthier.”

Kuehnert looks forward to this year’s silage crop and its potential to improve the ration even more.

“If we get some higher-power forages in this ration, it will really take off,” Kuehnert says. PD