Proper silage harvest management is the key to quality feed all year long, according to Rock River Laboratory in Wisconsin.
With forage inventories being low this year, it is more important than ever to make sure that the aspects of silage harvest that can be managed are managed well, Rock River Laboratory said. These aspects are harvesting at optimal moisture and proper chop length and achieving sufficient kernel processing, then following recommended storage practices.
“Taking time and putting in the effort to control the controllables will pay off with high-quality silage,” said Mark Kirk, business development and customer relations manager for Rock River Laboratory.
“To me, ideal harvest moisture is the single biggest key in harvest management,” he said, explaining that the moisture of the whole plant is indicative of the maturity of the plant. Harvesting corn silage at 65-68% moisture will ensure that the most important qualities of corn silage are at their best. Silages within this range will have ample, but not too much, moisture for good fermentation.
“Too wet, and you risk sloppy fermentation by promoting possible clostridial fermentation over lactic acid fermentation,” Kirk added. “Silages wetter than 70% moisture often leach out essential nutrients and sugars, lowering the energy content of the silage.”
He explained that silages exceeding 70% moisture also generally have decreased starch as a result of an immature plant, which, in turn, lowers the energy density.
On the other hand, silage that gets too dry has troubles of its own. “When silage moisture drops below 60% moisture, fiber quality and starch digestibility suffer,” Kirk said. “Packing becomes a problem, too, with insufficient moisture, causing incomplete or inadequate fermentation.”
The next most important condition of corn silage harvest is kernel processing. The kernel processing score (KPS) is used to measure how thoroughly the corn kernels are processed or broken down. “This score covers the percentage of the starch or kernels that will pass through a 4.75 mm screen on a Ro-Tap device,” Kirk said. “A good KPS score is 70% or higher.”
Kernel processing increases starch digestibility, which can directly influence milk production and feed efficiency. Kirk recommended checking the KPS on the first day of chopping and at least every other day, or when switching fields, in order to maintain a good score and adjust rollers if necessary.
Chop length or theoretical length of cut (TLC) is also another aspect that needs to be managed, Rock River Laboratory said. TLC is dependent on at least a couple of factors. “The wetter the corn silage, the longer the chop length can be — up to three-quarters of an inch,” Kirk said. “Drier corn silage needs to be cut shorter — maybe even down to three-eighths of an inch.”
TLC may need to be adjusted if the corn silage has undigestible neutral detergent fiber 240 (UNDF240) of greater than 12%, Kirk added. “There is some evidence that a shorter TLC may overcome the negative effects of UNDF240 on dry matter intake,” Kirk noted.
Once the corn silage is out of the field, proper storage is essential — and one of the most controllable variables. One thing that can help is placing a decision-maker on the pack tractor or bagger. “Many times, we leave these jobs up to someone less interested in how well the job gets done,” Kirk said. “Pushing all the air possible out of the silage during storage is imperative to proper fermentation. Using a research-proven inoculant is another added protection to preserve the quality of the silage you harvest.
“Most importantly, seal the pile or bag as quickly as possible, and ensure any holes are mended,” Kirk said. “Oxygen is one of the biggest nemeses to proper fermentation.”
Putting together a plan for best practices before harvest and working that plan to the best of your ability is essential to reach optimal silage quality.
“Check to make sure all of the controllables have been addressed before harvest begins, and ensure your team is on the same page to check each of them,” Kirk concluded. “When the coming year’s feed depends on those few short days of harvest and storage preparation, it pays to do it correctly and make sure those on the team know the importance, too.”