What is the Deep Litter Method

My favourite farmer, Joel Salatin, is essentially saying here that if you are on a livestock farm and it smells of manure, what you are smelling is poor management.

The typical smell of manure or slurry is caused by various nitrogen compounds. Ammonia (NH₃) is probably the best known of these. We all probably know what a good compost heap smells like: nothing at all. Good compost certainly should not stink. And yet nitrogen is an important component of every compost heap.

So why does nitrogen stink in a manure heap, but not in compost?

The answer is carbon. If there is enough carbon in relation to nitrogen (~30:1 C:N), the carbon binds all the nitrogen (because of chemical processes that I hope someone will explain to me one day :D), so that no nitrogen-containing gases can be produced. This eliminates the source of the smell.

Deep litter is therefore a layer of carbon-rich material on the floor of the chicken coop which, where possible, can become up to 45 cm deep. 15cm is the minimum depth for it to qualify as deep litter. The chicken coop therefore gets a slowly decomposing compost floor. The C:N ratio here should be well above 30 parts C to one part N, so that enough carbon is available to bind the nitrogen-rich chicken manure produced every day.

The rule is: as soon as you notice even a hint of ammonia, add a good layer of fresh litter.

Try to observe the situation closely enough that next time you add new litter before you can smell anything. Chickens have sensitive respiratory systems, and even low concentrations of ammonia that we cannot yet detect can be harmful.

Any reasonably fine material with a high carbon content is suitable.

For example:

• Wood chips
• Dry leaves
• Wood shavings
• Sawdust
• Straw (with some limitations)
• Chopped maize
• Nut shells etc. etc…

Whatever is easiest and cheapest for you to obtain should be sufficient. The important thing is that it is rich in carbon and not green. Green wood and leaves encourage mould growth. Straw can also be problematic if your chicken coop has an earth floor. The additional moisture from the ground can cause Aspergillus mould to develop in the straw, which can damage the chickens’ respiratory systems. If your chicken coop has a wooden or concrete floor, you can use straw as litter.

An earth floor has the advantage that microorganisms from the soil can migrate into the litter. (Caution: protect the chickens from burrowing predators if necessary.) It is a little like the difference between a compost heap and a bin in which plant waste is simply discarded. A compost heap in contact with the soil simply works better.

If you already have a chicken coop with a solid floor, do not go to the trouble of removing it or even building a new chicken coop. Instead, add some active compost to the first layer of litter (worms included). This gives you a similar effect.

The microbes responsible for composting need water and oxygen as well as C and N. The necessary moisture is usually supplied by the chicken manure itself. Problems are more likely to occur if the litter becomes too wet. This encourages the growth of pathogenic organisms and inhibits (aerobic) composting. The litter material should be as dry as possible without becoming dusty.

If the litter in the coop is too wet, replace and/or supplement it with dry litter and identify the source of the moisture. A drinker is often the cause, or the ground may have become too wet after prolonged rainfall. Drainage may be necessary.

The chickens introduce the necessary oxygen into the material by scratching. They turn the compost for us.

I do not want to give the impression that the purpose of deep litter is to produce compost. You can produce better compost more quickly with a compost heap. Finished compost is, however, one of the positive side effects of deep litter.

This brings me back to the interactions with the surrounding system that I mentioned above.

You therefore get compost that you can use as fertiliser and soil improver in your garden, on your pastures or in your fields. The deep litter stores the nutrients excreted by the chickens and creates a living ecosystem full of beneficial microorganisms.

This is where the real magic of deep litter lies. Active, beneficial microbiology provides better protection against various diseases than regularly disinfecting the chicken coop. Composting microorganisms produce vitamins K and B₁₂ and other immune-stimulating substances, which are taken up by the chickens because they are always finding and eating something interesting in the deep litter.

A study from 1949 shows a significantly lower mortality rate among chicks and greater weight gain in broiler chickens kept on well-matured deep litter compared with fresh litter.

Ussery describes this effect as alchemy. “What began as something repulsive and disease-causing was transformed into a substance that promotes health.”

Deep litter should therefore remain in the coop for as long as possible, because microbial activity increases over time. If you clean it out because you keep hitting your head on the ceiling ;), or because you need compost, you should leave as much of the “mature” litter in the coop as possible so that these positive effects are not lost.

The effects of deep litter are many and varied, and probably not all of them have yet been recognised.

• The biological activity in the litter makes the chickens healthier, gives them a wider range of potential foods, allows them to take in important vitamins and keeps them more active, because scratching in an interesting material is simply more enjoyable.
• As a result, they lay more nutrient-rich eggs and the meat improves.
• Your feed costs decrease and you have fewer problems with sick animals.
• You get nutrient-rich compost (be careful not to over-fertilise).
• This compost is full of microorganisms that enrich the ecosystem.
• As a result, your garden becomes more productive and your family healthier.
• The chicken coop does not stink, which is good for the chickens, their keepers and the neighbours.
• You have to clean out the coop much less often.

As you can see, a small change can have very far-reaching effects.

In almost 30 years of using deep litter, Ussery has identified only two disadvantages. Both relate to the earth floor beneath the litter.

The first problem is increased moisture in the litter during extreme rainfall (which occurred once in 30 years). Ussery solved this by adding a larger amount of very dry, fresh litter.

He eliminated the other potential problem – burrowing predators and feed thieves – from the outset by installing wire mesh extending 45cm into the ground beneath the foundation of the coop.

I find it difficult to come up with a conclusion for this section without repeating myself.

Deep litter is great. You have less work and more benefits than without it. The few disadvantages are easy to avoid and are not a real obstacle.

Why not give it a try?