Compost bedded pack (CBP) barns are an increasingly popular housing system for dairy herds, offering benefits like improved cow comfort, reduced lameness, and greater productivity. Research shows that when managed correctly, these systems can lead to better herd health and enhanced milk production.
What Is a Compost Bedded Pack Barn?
CBP barns feature a large, open resting area filled with organic material—typically sawdust or wood shavings—that composts over time. The heat generated by this natural process creates a dry, soft surface for cows to lie on.
Key Benefits:
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Enhanced cow comfort
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Reduced lameness and better mobility
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Improved heat detection
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Lower somatic cell counts in some herds
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Reuse of bedding material as fertilizer or finished compost
How to Manage Compost Bedding for Success
🧹 Annual Cleanout
Bedding should be completely cleaned out once per year—commonly in the fall or spring—depending on how you plan to use the removed material. Always leave 15–30 cm (6–12 inches) of the old bedding in place. This retained layer helps jumpstart microbial activity in the new bedding pack.
🌡️ When to Restart the Pack
Start fresh compost bedding when the weather forecast predicts at least 4–6 weeks with daily highs above 10°C (50°F). This warm period helps the composting process generate heat before colder conditions set in. Inadequate startup heat can lead to management challenges during winter.
🪵 Bedding Application: How Much to Add
Apply at least 30 cm (12 inches) of dry bedding—such as sawdust or fine wood shavings—to the barn floor. The goal is to prevent the mixing equipment from touching the ground. Depending on the barn size, cow numbers, and pack dimensions, several truckloads may be needed.
💧 Moisture Management: Keeping Bedding Dry
Moisture control is critical. Bedding should stay within 40–60% moisture content.
Quick moisture test: Squeeze a handful of bedding.
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If water drips out, it’s too wet—add more bedding.
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If it crumbles and falls apart easily, it may be too dry.
Bedding Addition Guidelines:
Add 10–20 cm (4–8 inches) of new bedding every 1 to 6 weeks, depending on humidity, stocking density, and pack condition. Increase frequency during humid weather, if the barn is overcrowded, or when moisture isn’t evaporating efficiently.
🔬 The Composting Process Explained
Effective composting requires the right balance of carbon and nitrogen with sufficient oxygen.
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Carbon source: Sawdust or wood shavings
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Nitrogen source: Manure and urine
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Ideal C:N ratio: 25:1 to 30:1
If you smell ammonia, your nitrogen level is likely too high—add more carbon-rich bedding to restore balance.
When properly balanced, microorganisms break down the material, releasing heat, water vapor, and carbon dioxide—resulting in dry, warm bedding that promotes cow comfort.
🔄 Stirring the Pack: A Daily Priority
Stir the bedding twice daily, ideally during milking when cows are out of the barn. Stirring adds oxygen and keeps the surface soft and dry.
Stirring Guidelines:
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Use a cultivator or rototiller to stir bedding to a depth of 30 cm (12 inches)
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Deeper stirring (e.g., with a chisel plow) can increase bedding temperature and reduce bedding volume needs
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After stirring, use barn fans and keep cows off the pack for at least one hour to help dry the top layer
🌡️ Compost Temperature Targets
Measure internal pack temperature 15–30 cm (6–12 inches) below the surface using a long-stem thermometer.
Ideal composting temperature:
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43–66°C (110–150°F)
Proper temperatures support microbial activity and ensure that composting continues effectively throughout the year.
✅ Key Takeaways for Dairy Producers
Compost bedded pack barns offer real advantages—but only when managed consistently and carefully.
Checklist for Success:
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Leave 15–30 cm (6–12 inches) of old bedding when cleaning out
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Start a new pack when temperatures are above 10°C (50°F) for at least 4–6 weeks
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Maintain pack temperature at 43–66°C (110–150°F)
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Keep bedding moisture between 40–60%
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Add 10–20 cm (4–8 inches) of fresh bedding regularly
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Stir bedding twice daily for proper aeration and comfort
A well-maintained CBP barn supports cow comfort, which in turn leads to improved milk yield, better herd health, and more sustainable bedding use.
