When you’re processing and putting up silage in any type of structure, it’s a complicated job, and potentially dangerous.

Silo Gas

• Let’s talk silo gas for a minute – also known as nitrogen dioxide.  It’s a normal part of the silage making process.  We start to see this gas a few hours to a day or so after a silo is filled – And then it’s produced for about 2-2.5 weeks
  

  Silo gas is created in ANY type of silage storage system, but is a particular problem in tower silos.

  depending on conditions – Silo gas is produced
  in ALL kinds of silos – tower silos, bunkers, piles, bags – the biggest issue however, is when it’s a confined space.  This could be in a tower silo, an adjoining room, the chute or in the space between silo bags.

• In the air, nitrogen dioxide has a faint yellowish color though in low light conditions, you probably won’t see it…It smells a bit like bleach.  It is very irritating — even a few breaths can cause serious health problems.
• Avoid silo gas, especially during that initial three-week post-harvest window. Treat a tower silo and areas surrounding stored silage as a confined space.  Ventilate thoroughly – generally with the blower.  Get more information – entering any confined space incorrectly has deadly consequences.

Bunker Silo Rollovers & Other Issues

• There are special hazards with packing a bunker silo.  Some great detailed information can be found in this piece from Penn State on horizontal silo safety.
• Tractor rollovers occur every season while people are packing bunkers and piles – It’s critical that you select the right tractor – it MUST have a ROPS (rollover protective structure) and a seatbelt.
• A wide front-end is also an absolute must. Front-wheel and front wheel-assist tractors provide extra traction and stability for packing. Duals usually increase stability as well as appropriately-placed weights.
• Backing a tractor up ANY slope is preferred – you achieve better stability AND CONTROL.
• On a slope – as you fill a bunker, make sure your packed, wedge-shaped surfaces are not too steep – We generally talk about a safe slope being 3 to 1 or something even less steep. On a pile or bunker that’s 20 feet high, you need a wedged surface do drive up that’s at least 60 feet long in the horizontal direction.  Anything less, and you run a great chance of rolling a tractor.
• There are many other precautions to take with your employees and family members who are working at this time…Like these:
  • Only experienced people should be permitted to operate equipment.
  • Require all equipment operators to remain in their vehicles to avoid being run over.
  • Keep visitors and children out of ANY farm work zone.  A packing operation seems cool and fun to watch – but operators have a lot to pay attention to, and the chaos associated with visitors and bystanders can be very distracting.
  • Have workers wear brightly colored safety vests or t-shirts to increase visibility.

This post was originally developed to support a series of silage harvest-related podcasts posted by colleague Liz Binversie of Brown County, UW-Extension.  This one is written to connect to the podcast covering processing and packing

August is the time to start planning and making arrangements for silage harvest. It’s also a good time to bring the team together and make a checklist of what needs to be done to ensure nothing gets missed, said Rory Lewandowski, Extension Educator at The Ohio State University.

Starter checklist:

• Speak to harvesting team or custom harvester
• Check the chopper to ensure it’s in excellent working condition
• Line up equipment, including hauling trucks or wagons and packing tractors
• Make sure there are enough properly trained people on-hand to use equipment
• Have pile covering materials ready for use

Monitor Moisture

“With corn silage harvest, you’ve got one shot to get it right and you’ll be using that silage for about a year, maybe longer,” he said. “It’s so important to get dry matter content right because if you don’t, you’re going to really struggle.”

Ideally, target 35% dry matter (DM) for all your silage, but the range is 32% to 38% DM. There are some issues if silage is harvested too wet or dry, but if you must err, Lewandowski recommends harvesting wetter rather than running too dry.

“Typically, corn silage dries down about ½ percentage point of moisture each day. Last year, we ran into a warm streak and were at ¾ percentage point a day, so it went from ‘not quite ready’ to ‘should have harvested yesterday’ very quickly,” he said. “So, you’ve got to monitor daily.”

Length of Cut

Length of cut is critical to fiber digestibility. While fine, small pieces make for easy packing and exclusion of oxygen, they don’t make effective fibers in the ration or the rumen.

“If you’re not using a kernel processor, the theoretical length of cut should be set at ¼ inch to ½ inch,” he explained. “But if you are using a kernel processor, it helps to increase the availability of starch, so we cut a little bit longer at ¾ inch. Those who are shredding the whole plant length-wise can cut bigger pieces – up to 1 inch.”

Inoculants

There are two types of inoculants to consider:

1. Lactic acid – if in past years you’ve struggled to get a good fermentation, use a lactic acid bacteria at the point of chopping. It helps produce more acetic acid and drops the pH.
2. Lactobacillus buchneri – If you’ve had problems in the past with feed out and spoilage, then consider adding a L. buchneri inoculant. It helps to increase the stability of silage. It also boosts your acetic acid, which works on spoilage organisms to like yeast and mold, especially as you open the face up.

“There are a lot of good inoculants on the market. Do your research,” he advised. “Also, make sure you use enough and be cognizant that these are living organisms. Don’t use chlorinated water and watch the water temperature.”

Excluding Oxygen

“Oxygen and air are the enemy of silage,” he said. “Packing helps us to exclude it, but a lot of producers have a hard time measuring it. The goal is to have a density 42 to 45 pounds per ft3 of silage as its delivered to the bunker silo. On a DM basis, that’s a density of 14 to 16 pounds per ft3.”

To get there requires having enough weight to pack and packing in a timely manner. A few tips:

• For every ton of silage, you need 800 pounds of weight for packing. If delivering silage at 50 tons per hour, multiply that times 800, and it tells you 40,000 pounds of packing or 20 tons of tractors (or packing equipment) are needed for packing
• Never put down more than a 6-inch to 8-inch layer
• Pack that well
• Apply another 6-inch to 8-inch layer

The goal is to harvest quickly. Once you’re done, it’s critical to cover the silo as soon as possible to keep oxygen out and protect it from the elements.

“In recent years, research on a two-step covering product where they have the oxygen barrier sealing and a regular piece of plastic over the top has shown to help with fermenting high-quality silage,” Lewandowski said. “Research has shown that putting plastic on the inside wall of your bunker silo can help to increase the quality of that silage as well.”

Once covered, seal it either using bags with weights or cut tires that are touching one another. If you’re bagging silage, make sure it’s packed tightly but consider leaving the end open for a day to release some of the air and gas, then seal it up tight, he noted.

Safety Tips

• Big equipment visibility is often very limited, so always keep children away from the area.
• Plan a pre-harvest meeting with silage crew and farm employees, especially those not directly involved in the silage process to share what’s going to be happening to minimize their risk.
• Don’t pack silage above walls.

Now is the time to do corn chopper maintenance, giving you time to order new parts if needed.

“To ensure the entire chopper is in good condition, replace nicked knives and the shear bar if the edges are smooth,” Michelle Jones, with the University of Kentucky. “If the rollers are showing signs of wear, replace them.”

Rollers typically have a life span of about 60,000 tons of corn silage, she says. “Irregular wear of the roller teeth can prevent the narrowing of the roller gap, resulting in insufficient damage to the kernel which can lead to reduced starch digestibility for the cow.”

The ideal roller gap is 1 to 2 millimeters, and a quick way to check proper gapping is to use a dime. A dime is 1.2 mm thick. “Place the dime between the rollers and if excessive space is found, the tighten the roller gap,” she says.

Once in the field, you can check if processing is correct by scooping a sample of silage into a 32-ounce cup, explains Donna Amaral-Phillips, a dairy nutritionist with the University of Kentucky. Spread the sample on the ground and count the number of whole or half kernels. If you have less than two whole or half kernels per cup, processing is ideal. Two to four whole or half kernels per sample suggests processing is adequate, but more than 5 whole or half kernels means adjustments to the roller should be done.

To ensure the samples are representative, take sample from three different loads. At a bare minimum, take three samples at the end of each day.

“If the results of kernel processing are not monitored during harvest, starch digestibility may be reduced,” says Amaral-Phillips. “Once the silage is chopped and stored, fixing mistakes made during harvest is difficult.”

You can read more about chopper maintenance and adjustments here.