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Silage Bunker Management

A silage bunker is a large part of a dairy's feed supply, and how you fill, cover and feed it affects quality and safety. Here is a practical walk through the main steps.

Why bunkers need steady management

Silage depends on keeping air out and acid in. When air gets in, quality and dry matter are lost, and spoiled feed can cause problems in cows. Most of that loss is preventable through steady practice at filling, covering and feedout.

Good bunker management is repeated habits, not a single big job.

Different crops and different weather call for different adjustments. Ask your extension specialist how your corn silage, haylage or other forage should be handled, since moisture and chop length affect how well it packs.

Preparing the bunker before harvest

Clean the floor and walls and repair cracks and holes. Check drainage so water does not flow under or into the pile. Have plastic, covering material and weights on hand before the first load arrives.

Plan the crew and equipment ahead. Packing tractors, dump trucks and loaders should have a clear traffic pattern, and everyone needs to know the plan.

Walk the bunker with your crew before harvest and talk through the order of work. Agree on who watches the packing tractor, who covers, and who stays off the pile.

Filling and packing

Spread forage in thin layers and pack it well. The aim is to push out air. Work with your extension specialist or silage consultant on target moisture and layer depth for your crop and equipment.

Keep the pile shape safe. A pile that is too steep at the sides or at the face is a hazard to the packing tractor and to people working around it. Follow equipment manufacturer guidance, and use a rollover protective structure and seat belt.

Compaction tractors should be heavy enough to pack well but safe on the slope. Keep the speed steady and the pile shape even. Extra passes at the edges and corners pay back in less spoilage later.

• Fill in thin, even layers
• Pack continuously during filling
• Keep the surface crowned for drainage, not steep
• Do not let people walk on the pile unprotected

Sealing and covering

Cover as soon as filling ends. Use plastic suited for silage, overlap sheets, seal edges against the wall and weigh the cover down well so wind and animals cannot lift it. Many farms use a sidewall cover as well.

Check the cover regularly for tears, pooled water and gaps. Patch damage promptly. Keep birds, rodents and pets off the pile.

Remove the cover only as far as you will feed in a day or two, then replace and weigh it. A cover left open for days lets air work back into the feed.

Feedout and face management

A clean, smooth face limits air entering the pile. Remove silage in a way that does not leave loose feed behind. Take feed from the whole face, top to bottom, rather than gouging one spot. Ask your extension specialist about the feedout rate that works for your herd and weather.

Do not undercut the face. Silage can collapse and cause serious injury or death. Keep people and vehicles away from the face, and never stand under an overhang.

• Remove a fresh layer across the whole face
• Never undercut or leave an overhang
• Keep the face tidy and free of loose feed
• Discard any spoiled or moldy silage and keep it out of the ration

Safety around bunkers

Hazards include rollover, face collapse, run-over incidents and falls from walls. Keep children and visitors away. Use signs and barriers, and train all workers.

Gases can build up in sealed or freshly filled silos and some other structures. Follow OSHA and NIOSH guidance for all forage storage, and do not enter any confined space without training and a plan.

Keep a first aid kit and a working phone at the bunker, and make sure someone always knows who is working there.

Records and review

Write down fill dates, field and crop details, weather, packing notes and feedout rates. Send samples for lab analysis through your nutritionist or consultant. Records show which practices work and help you plan next season.

Review each year with your nutritionist and crew. Ask what went well and what you would change.

Share what you learn with the crew so the next fill goes better. Even a few lines in a notebook, kept every year, can help the next person who runs the bunker.

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