Fall is here, which means corn silage harvest is in full swing for many livestock producers across the Midwest. If you are still waiting for the chopper to pull into the yard, make sure a plan is in place for harvest targets to ensure a high quality silage pile is produced. Here are a few areas to check before chopping starts.
Strive to chop corn silage at 35% dry matter or 65% moisture for optimum packing and fermentation. Moisture can be monitored prior to chopping using a microwave oven or Koster tester. Once a moisture is known, dry down rate of 0.5% per day, is a common rule of thumb and can help plan for when the chopper needs to show up. For details on how to check moisture at home, see Moisture the Critical Component to Good Silage.
Corn silage should be chopped between ¼” to ½” (without kernel processing) or ¾ inch (with kernel processing) Kernel processing unlocks the starch and increased digestibility of corn kernels in the silage pile. To evaluate kernel-processing score during chopping, collect 1 liter of chopped silage from a few trucks each hour and count the number of whole kernels present. Properly processed corn silage show have 0 to 2 whole kernels present. If more than two kernels are found, the chopper needs to adjust either length of chop or roller mill gap.
Silage is packed into a pile in order to remove air and create an anaerobic environment with pH of 3.8 – 4.2 so to properly ensile and preserve forages. Silage preservative inoculants can be added to the silage as it is dumped in the pile to help decrease nutrient loss by increasing conversion efficiency of sugars to lactic acid and inhibiting yeast growth. The person packing silage will work the longest of anyone one the crew; however, it is their job to make sure the high quality fresh product maintains ideal feed quality through feed out.
Size and shape of the silage pile needs to be considered before chopping begins also. In general, silage cannot be over packed except for the top layer. Spending all the time on the top, does very little for the whole mass. For every ton of silage that is delivered to the pile, 800 lbs. of pack tractor is required. So if 100 tons are delivered to the pile per hour, 80,000 lbs. of tractor required (example: usually two heavy pack tractors and one push tractor). Drive over piles are best to ensure all sides of the pile get adequately packed and steep sides should avoided to reduce chances of roll overs. Using a 1:3 ratio is recommended: for every 1 foot of vertical height, three horizontal feet should be contributed to the side of the pile (example: 10-foot high pile should have 30 foot on each side).
Silage piles that are left uncovered have significant losses in dry matter due to exposure to environmental elements and improper fermentation. Therefore, covering piles with 6 – 8 mm white plastic will seal the pile, keeping oxygen and excess moisture out. Plastic should be weighted down with tries to keep it tightly secured and prevent air from blowing under the plastic. Keep silage covered for at least 45 days before feeding to allow fermentation process to occur.
Chopping silage is an expensive process once expenses of the chopper, preservatives fuel and labor are accounted for. Utilize the Silage Earlage Decision Aid for assistance pricing silage.
For assistance sampling, pricing or ration balancing with silage, contact an SDSU Extension expert.
- Silage Zone Manual. 2nd Edition. Dupont Pioneer.
- ISU Extension and Outreach Northwest Iowa Corn Silage Clinic. 2018