Harvesting corn silage at an adequate particle size is not only critical for its preservation, but also for adequate rumen health and overall dairy cow performance. The smaller the particle size the greater the potential for adequate compaction and preservation. However, smaller particle size lacks effective fiber to stimulate cud chewing and can result in acidosis in dairy cattle. A new method of harvesting corn plants for silage has been developed in South Dakota. The system is named “shredlage” by the developer Scherer Corrugating & Machine, Inc. of Tea, SD and consists of a different type of processing rolls mounted in a conventional harvester.
Whole-plant corn silage plants go through a self-propelled forage harvester fitted with cross-grooved crop processing rolls that “shred” the corn plants during chopping. The roll’s action is similar to the way the molars of a cow work. The surface of the cow’s molars also has grooves and ridges. In addition, cows don’t chew vertically, but rather horizontally which results in “shredding” rather than cutting feed. This accomplishes two things: 1) It disrupts the forage fiber and corn kernels allowing for greater nutrient digestibility by the rumen microorganisms, thus enhancing fermentation both in the silo and the rumen and 2) It still allows for an adequate particle size to supply effective fiber to stimulate adequate cud chewing by the cow.
Research conducted by the University of Wisconsin suggests that shredded silage still maintained an adequate packing density of 17.5 pounds of DM per cubic feet compared to 17.2 of the conventional kernel processed corn silage. The proportion of coarse particles retained on the 19 mm screen of the Penn State Particle Separator at feed-out was 31.5% versus 5.6% for the shredlage and kernel processed corn silage, respectively. Once the shredded and kernel processed corn silages were fed, milk yield tended to be greater (100.1 pounds/day) in cows fed shredded vs. those fed kernel processed corn silage (97.8 pounds/day). The key to successful application of this technology would be to determine if feeding shredded corn silage results in less risk of acidosis in high producing cows. In addition, it will be necessary to ensure that shredlage allows for adequate processing of the corn kernel to ensure maximum starch utilization by the cow. Being able to maximize the inclusion of corn silage in the diets of high producing dairy cows will allow for the reduction of highly priced corn grain.
Wim Hammink, dairy producer from Bruce, SD, decided to try this new technology in his herd of dairy cows. Hammink decided to go with the shredlage processing unit for the following reasons: “First, by using the shredlage processor we can tear up the particles that come though the chopper sideways. This creates additional surface area for the rumen bugs to work on. Secondly, we should get more feed value out of our silage by increasing the surface area. Also, with a longer chop length (about 1") we can feed more corn silage and less hay. Lastly, he feels another advantage is that with the shredded particles the corn silage pile is better packed and we can hold more corn silage in our storage area.”
The pictures below show the difference in normally processed silage (taken after fermentation) and shredlage (taken before fermentation).
Picture 1. Above: Traditionally processed silage after fermentation.
Picture 2. Above: Shredlage prior to packing and ensiling..
Picture 3. Above: Traditionally processed fermented silage (left) Shredlage that is unfermented (right).