Corn shredlage has piqued the interest of many dairy producers and nutritionists due to the benefits of more physically effective fiber (peNDF) and highly processed kernels.
Our group of dairy nutritionists has been quietly supportive but cautious given the limited research on its benefits. We learned more about shredlage along with some of our clients in eastern Wisconsin this fall.
My associate, Matt Waldron, helped adjust choppers fitted with shredder heads by shaking hundreds of samples for multiple farms and custom harvesters through a four-box Penn State forage separator. He quickly realized that the suggested roll settings on shredlage units were only starting points. There were too many unprocessed kernels and long sortable pieces of stover.
During the course of evaluating the silage through the shaker box, we developed our own set of guidelines for what looked like good feed.
In the top box, look for ripped or shredded material that will pack well and reduce sorting. Particles that are sortable by the cow indicate that equipment settings need to be adjusted. We recommend 15% to 25% in this box; low grain or drought-stressed corn might be higher.
In the second box, when the machines were set properly, the kernels on this screen were shattered. They were typically about the size of a half kernel but were either empty kernels or severely "tortured" so the starch is more quickly available. We recommend about 55% to 60% in this box.
Shredlage sample in a bucket before particle separation.
The small pieces of kernels and kernel contents ended up in the third box. We recommend 22% to 27% in this box. The fourth box contained less than 3%.
In our opinion, more than 25% retention in the top box may create packing problems, especially in drier silage. It may also lead to sorting in the finished product. Careful monitoring through the entire harvest is imperative as field conditions change.
Separated shredlage fractions from the four screens of a Penn State shaker box.
We worked with Claas, Krone and John Deere units during this harvest test. Although we observed some very obvious differences between brands, we expect that the technology gap between the brands will close very quickly.
It took most of a day on some farms to dial in a chopper, so it’s important to stay on top of it to avoid putting up too many mistakes. Given the variability, a minimum of four truckloads and three to four samples per truck should be shaken before making chopper adjustments.
With the exception of one machine, we harvested at maximum theoretical length of cut (26 mm to 32 mm) and adjusted particle length by tightening the rolls. The maximum roll gap out of all units was 1.9 mm.
Tightening the rolls to the "sweet spot" often resulted in choppers running slightly slower than normal (4 to 5 mph). But we did not find that it was necessary to bog down the machines in order to get good feed.
In the end, after shaking hundreds of samples, our dairies were pleased that Matt was there to monitor the harvest. We have a favorable view of shredlage and are confident that well-adjusted shredlage units will result in superior kernel processing, as well as more peNDF across farms and field conditions, compared to traditional corn silage.
RICK LUNDQUIST, Lundquist & Associates, Nutrition Pro-fessionals, based in Duluth, Minn. You can contact him at firstname.lastname@example.org.