Corn Silage Harvest: Want More Money in the Bunker?

Producing high quality corn silage isn’t easy, but the goal is to preserve as much dry matter nutrient content as possible. To do that, it’s important to harvest at the correct moisture and to pack well to ensure the most valuable parts of that silage – sugars and starches – aren’t burned off.

“Corn silage per acre can produce a lot of ‘tons of feed material,’ and it looks great on paper. However, the amount of loss that can occur during harvest and packing can make that material go from cost effective to something that’s very non-cost effective,” said Mary Drewnoski, associate professor at the University of Nebraska-Lincoln.

Harvest Speed & Tractor Weight
“Cow-calf producers tend to use custom choppers, who are really good at their job,” she said. “However, they get paid by the ton, so they want to go as quickly as possible. For producers who are not set up to handle a lot of ‘tons of material’ really quickly, they can end up not getting a good pack. I see some losses near 50% simply because of poor packing.”

Target about 800 lbs. of tractor weight per ton, per hour. Drewnoski suggests producers ask their neighbors to help with packing, pay for custom packing or consider paying to get it bagged.

Layer Thickness
The maximum loose material thickness should be 6six to eight inches, but if producers can get down to three inches, they’ll get a better pack. Especially for producers who don’t have enough tractor weight relative to volume coming in, the thinner the layer, the better.

“We recommend targeting about 15 pounds of dry matter per cubic foot or about 45 pounds of as-is silage per cubic foot,” she explained. “If you aren’t hitting those targets, it’s usually one of two things – not enough weight or too thick of layers.”

Target Moisture Level
Hitting the sweet spot with moisture for the entire crop can be daunting. Corn silage can move from being ready to harvest to overly dry very quickly. Drewnoski suggests starting a little wetter, especially if you have a lot of fields to harvest. Ideal moisture is about 60% to 65%. So, start harvesting, as you near 65% to 67% moisture. Wetter material can assist with the pack as well.

Length of Cut
For beef cattle, unless operating a feedlot, try a finer length of cut like less than ½ inch. A finer chop helps to get a better pack. This might be a challenge with a custom harvester because it takes more time to harvest, but it can help get a better pack. For dairy, stick to a higher length of cut like ¾ inch to reach effective fiber for the rumen.

Covering is Critical
Covering silage immediately is best to limit exposure to oxygen, but covering within 24 hours can still be beneficial.
“In the beef industry, producers do not typically cover silage, and it’s an area where we need to learn from our dairy friends,” she noted. “Dairy producers have literally seen the benefits of covering silage for decades, but beef producers don’t understand the value, and it results in significant losses in quality and tonnage.”

Many cow-calf producers harvest using piles, which create a lot of surface area that if not covered, can result in a lot of loss. Most believe they are only losing a few inches of material, but without covering, producers will lose material three feet deep on any exposed surface area.

“What people don’t understand is that it’s not what they see that is making a difference, it’s what they don’t see,” she said. “For fermentation to occur, oxygen must be excluded. Without covering, instead of starting fermentation, the material remains in the aerobic phase. This phase grows bacteria, mold and yeast, who munch away, eating all of your good material and creating significant losses.”

Safety First
It is very dangerous to walk up to or near the silage face. Use the tractor bucket to pull material straight down. Always get the material out of the tractor bucket when taking a sample.
It’s important to remind family, friends and anyone who’s visiting the farm that the silage bunker or pile is a danger area, and they always need to stay away from it.