Whether using conventional kernel processors or the new Shredlage units that slice silage corn longitudinally, operators could do a better job of making sure kernels are crushed. That will maximize the feedstuff’s digestibility, says Mike Hutjens.
“The word on the street is, the Shredlage unit does a better job of crushing the corn kernels,” the University of Illinois emeritus dairy nutritionist admits. “But if we get the kernel processors down at the 1-2 mm (roll gap), we can still crush the kernels. We can still do a better job with a traditional kernel processor or a plant (Shredlage) processor.”
“The theoretical length of cut (TLC) that seems to offer the best kernel crushing using Shredlage rolls is at 26 mm, or just more than an inch,” says Roger Olson, nutritionist and Shredlage technical director. That compares to the 19 mm, or ¾”, TLC with a 1- to 3-mm roll gap recommended for conventional kernel processors.
Shredlage processors come at a price of nearly $30,000, while kernel processors are part of the package when buying self-propelled choppers. But producers who’ve used the new technology find cows consume more corn silage and produce a greater amount of milk – 2-4 lbs/cow/day, Olson adds.
Silage corn shredded at a longer length provides dairy cows with increased amounts of effective fiber, as University of Wisconsin data show, Hutjens says.
Using the three-box version of the Penn State Forage Particle Separator, he checked the particle size and kernel crushing of a Shredlage sample from a Wisconsin dairy. Forty-four percent of the forage stayed in the top box, 27% in the middle box and 29% in the bottom. A few corn kernels, some partially crushed, were found in the second and third boxes.
He compared that to an Illinois grower’s “winning sample” of kernel-processed corn silage. It shook out 13.3% in the top box, 68.8% in the middle and 17.9% in the bottom. Few kernels were found in the second box, and “pulverized kernels” were found in the third box, an “exceptional” example of processing, Hutjens says.
The problem is, kernel processors are rarely set correctly or monitored consistently to obtain those kinds of winning results. “Everybody says they chop at ¾” until I get my ruler out and measure it,” he says.
“If you go to Vegas and bet money, you’re probably going to win with Shredlage. But my argument is, you can narrow that difference by chopping (with kernel processors) at ¾”.
Ideally, 70% of the forage mass should be found in the top two boxes, and there should be no kernels in them regardless of processing method. But producers depending on kernel processors will have to be diligent in making sure they’re working correctly.
“Will that slow you down? You betcha. Will it cost more fuel? Probably. But, then again, we’re looking at that vs. straw, which has its own inherent risks, or $300/ton alfalfa, which also has some economic ramifications.”
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