It may only be early August, but the idea is to have your corn harvest equipment repaired and adjusted before it’s time to chop in case you need to make repairs and /or order parts. Now is the time to check over your forage harvester, and your silage processor in particular.

Several factors affect silage processor roll wear and tear, so there’s no rule of thumb as to how many tons of corn you can chop before the rolls are worn enough to cause problems. John Deere sells a tape to wrap around the processor roll that indicates if it’s time for a replacement. Several measurements may be necessary, since the rolls don’t wear uniformly. A custom operator I know suggests that a good way to judge processor status is to run your finger along the conditioner edge, and if it nicks your finger it’s still sharp enough. Use discretion if you attempt this, and don’t ask for a demonstration!

We know from experience (of others, fortunately) what can happen when you try to squeeze one more year out of worn processor rolls. Some years ago I was finding a large number of whole kernels in the corn silage on a local farm. I was surprised since this was (still is) one of the top dairy farms in the Northeast. The farmer saw me looking suspiciously at the corn kernels and said “You caught us. We tried to get one more year out of our processor rolls, and now we’re paying the price.” At least he realized what had happened. If rolls are worn even tightening the roll clearance to 1 mm won’t solve the problem.

Speaking of processor roll clearance: Opinions differ, but maybe we never should have mentioned a 3 mm clearance as being acceptable. We used to say “start at a nickel and end at a dime,” suggesting that as the corn crop matured and kernels got harder farmers should progressively reduce roll clearance from 3 mm to 1 mm. There has to be some reason why so many kernel processing scores (KPS) are so-so. Most choppers have more than enough muscle to process corn at 2 mm without slowing harvest. On a positive note, processing scores have been steadily improving.

Finally, it seems that an ever-increasing percentage of corn for silage is harvested by custom operators. Most are highly reputable and want to do a quality job for their customers, but even so it’s up to you to monitor the crop coming out of the field. As a guideline, there shouldn’t be more than one unbroken kernel or two halves in a quart of processed corn. If you’re so involved in the harvest process that you don’t have time to monitor processor effectiveness, then change something so you can.

Located in northern New York, the William H. Miner Agricultural Research Institute conducts research programs that apply basic science to contemporary problems confronting the dairy industry, with a focus on the crop-animal-environment interface, and cow comfort and behavior.