What is a deep litter barn?
A deep litter barn is a building in which livestock move freely and the manure is allowed to accumulate in a thick layer of bedding. The animals stand on straw; fresh straw is added regularly on top, so the pack of manure, urine and straw grows steadily deeper. Once the layer gets too high or too soiled, the whole mass is cleared out and spread on the land as farmyard manure.
The Dutch name is potstal, from potten, to store up. The floor is deliberately sunk below surrounding level so the pack can grow without the animals’ heads coming up against the roof structure.
Historical importance
On the sandy soils of the eastern and southern Netherlands, and in comparable regions of north-west Germany, this system drove the farm economy for centuries. Sheep and cattle stood on heather sods; the mixture of sods and manure went onto the arable fields. That centuries-long manuring produced the characteristic raised fields — essen or enken — around the old villages, arable land built up literally by metres. No deep litter, no esdorp.
The modern deep litter barn
For large-scale dairying the system is impractical: it needs a lot of straw, a lot of space per animal and a lot of labour. Deep litter barns today are found mainly on smaller and often organically minded farms, and in pig and suckler beef systems that aim at welfare and solid manure. The welfare advantage is real: animals can lie, walk and behave in ways that a slatted floor does not allow.
Besides straw, wood chips, sawdust and other organic residues are used as bedding.
Construction points
- Sunken floor with a retaining wall. The pack has to be contained. Expect anything from a few decimetres to over a metre of depth, and a wall able to take the lateral pressure.
- Impermeable floor. Manure storage inside a building falls under environmental regulation. The floor must be manure-tight, and leachate must not reach the soil or groundwater. Check the rules that apply locally.
- Clearing-out opening. The building must be emptiable with a loading shovel. A deep litter barn without a wide, high door at the gable end becomes a problem later.
- Ventilation. A composting pack generates heat and ammonia. Generous ridge ventilation and open eaves are essential for animals and people alike.
- Self-heating and fire risk. A thick, damp bedding pack can heat up considerably. Keep a distance from timber structure and electrical installations.
- Bearing capacity. A full pack is heavy. Include that load in the design of retaining walls and foundations.
Related terms
- Barn
- Cubicle house
- Slurry store
- Agricultural building
- Farmyard manure
- Shed
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