Making Silage Out of Dry Corn
August 17, 2012
Most dryland corn fields currently are too dry for making the best silage. Dry silage is difficult to pack well enough to force out all the oxygen and it often spoils, lowering its energy and protein digestibility. It also can heat up, leading to spontaneous combustion fires.
Adding water to increase moisture content is next to impossible. It takes about 7 gallons of water for each ton of silage to raise moisture content just one point. Even if you have enough water, the chopped corn can’t absorb it fast enough to do any good.
In this situation a better solution is to blend a wetter feed, like fresh alfalfa, forage sorghum, or green soybeans with dry corn or some corn that’s still quite green. Getting the right combination may require two choppers and can be tricky but done right, it can produce excellent silage.
If you do chop dry corn, remember that your main goal is to minimize oxygen in the silage. Adjust knives to cut finer and do some extra packing even if the chopped corn seems to spring right back up. Save your wettest forage for the top layer. This helps add extra packing weight and gets better sealing. If you do have water handy, apply it to this top layer for even more packing weight. And, of course, always cover dry silage with plastic to prevent outside air from seeping in or even better, pack and store it in silage bags.
If corn is too dry for silage, another option would be to dry it down and cut it for hay or graze it like winter stalks.
Ensure Complete Fermentation Before Feeding
Making silage from drought-stressed crops often is a good way to safen these feeds. Usually the fermentation process will reduce its nitrate content.
However, during the first few days of early fermentation, the chopped forage begins to heat, converting those nitrates first into nitrites. And, nitrites are as much as 10 times more poisonous to cattle than nitrates. Later, these nitrites are neutralized and converted into other compounds that are less toxic.
If you feed your freshly chopped forage before it has completed its full fermentation cycle, you risk giving your cattle a highly poisonous forage filled with nitrites. To avoid this, wait three or four weeks after chopping before feeding fresh silage. Then, test your silage for nitrates before feeding.
Extension Forage Specialist