Striving for a better kernel processing score

By Jon Orr

The author is a partner in Orrson Custom Farming Ltd., Apple Creek, Ohio. He is past president of the U.S. Custom Harvesters Inc.

I want to take a swing at a kernel processing article. We all have read so many thoughts on the subject, what new light could I add? Maybe nothing, but with some of the dismal kernel processing scores (KPS) that are still being achieved, I am ready to pick up a ball bat and swing hard. So here it goes . . .

Since kernel processors (KP) were conceived in the early 1980s, the industry has evolved significantly. The first machines to use a KP would have struggled to cut 100 tons per hour and were merely trying to nick the grain. We could probably set our current day KP at 4 or 5 millimeters (mm) and achieve the “nick” or “crack.” At this setting, rolls and bearings last hundreds of thousands of tons, fuel consumption is less, but milk production suffers.

We all embrace the goal of more milk production. We all understand that the old standard of processing is not acceptable. So why are KPS scores often low? I am not going to put pretty graphs and charts in the middle of this article to prove what we all know is happening — way too many harvesters are not making the grade!

The failures are not limited to the custom chopping guy. Many dairies cutting their own are getting dismal scores. I have seen as low as a 24 KPS. There is an attitude at some locations that if we are getting 80 to 85 pounds of milk with a 50 KPS, then that’s good enough. I guess that attitude would help with the milk surplus we have right now, but it sure does not help a dairy’s bottom line.

Many factors at play

How do we fix the problem? This is where it gets complicated. It’s not just about the unit or processor type, be it conventional, shredlage, self-propelled, pull-type, green, blue or pink. Kernel processing scores for all of these can range from horrible to great.

Corn at one farm or field location will process easier than at another. Some corn hybrids get easier to process as they mature, while others become more difficult.

I compare our silage harvester to a race car. In NASCAR, a winning team is constantly evaluating performance, adjusting suspension, tweaking the engine and changing the tires. Have you ever seen the huge pile of tires that get used at every race? That same level of attention and adjustment needs to also happen during silage harvest.

Everything from the performance of the corn head to the obvious amount of wear on the KP rolls contributes to the final KPS. As a processor wears, the roll gap needs to get tighter. As the roll gap closes, the length of cut might need to be a bit longer. If the wear parts on the head are about shot, the head will slug feed and the KPS will suffer. If your drum bottom is not set right, the crop flow will slug feed and KPS will suffer. If the accelerator is worn or out of adjustment, the crop will not get away from the KP and KPS will suffer. It’s almost as tricky as the race car!

Monitor during harvest

How do we judge (guess) at the processing score while we are cutting? Do we use the 32-ounce cup method? If so, what is considered a whole kernel? What is considered a half? Does the size of the whole kernel not get factored in? What about a bucket of water and looking at just the grain portion? How long does it have to soak in the bucket before all the grain sinks? How many large kernel chunks are allowed per handful of silage in the water bucket?

Maybe we use the 32-ounce cup to put the right amount of silage in the bucket. Is this a representative sample of what is coming out of the spout from this whole field? Can we buy a testing setup and check samples just like the labs — but at the farm? My point is that the number of variables is endless and the official KPS is always well after the harvest is over.

Is there any way to make sure that we get a good KPS? YES! Train your whole team on the importance of processing. Make sure they know how to use a Penn State shaker box because we can actually over process. High scores require all kernels to be totally destroyed and this also can shorten the particle length to the point effective fiber in the rumen becomes a problem.

Teach the truck drivers to watch for large kernel chunks on their truck hood (somehow silage might end up there every now and then). Teach the pushing tractor operators to look for large kernel pieces. Make sure the chopper operator totally understands the cutter. Problems such as head slugging need to be “felt” or identified from the seat of the harvester. Visual inspections of the silage need to happen often through the day and in a safe place. This safe place is not on top of the pile with tractors pushing around you. Make it a practice to thoroughly check out the processor daily.

Bearing temperatures are monitored on some machines from inside the cab; if your machine does not have this option, then buy a temperature gun and check bearings daily. Always have the machine shut off when making this check and replace parts as needed. KP rolls are very aggressive when brand new; once initial sharpness is gone, adjustments might be needed. Eventually, rolls will wear out and need to be scrapped. Like tires at the racetrack, don’t wait too long. Sooner is better than later.

Every color of machine and processor type can do a great job or a horrible job. The pit crew is the difference between winning and losing in both NASCAR and silage harvesting. If we are constantly monitoring our performance, and making adjustments, we will quit getting our butts kicked by the KPS.
Are you ready to start winning?

This article appeared in the February 2016 issue of Hay & Forage Grower on page 16.

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