Why We Use Bokashi Bran in Our Cattle Bedding

Here at Lower Blakemere Farm, we use Bokashi Bran in our deep-litter cattle sheds.

It’s a very simple addition to something we’re already doing. As we put down fresh straw, we scatter Bokashi Bran through the bedding, concentrating a little more on the wetter and muckier areas. Then the cattle do most of the hard work for us, trampling the bran through the straw, dung and urine as the bed builds.

What interests us isn’t simply making the shed smell nicer — although we certainly notice a difference in that sharp ammonia smell. It’s about starting to manage the biology of the manure before it ever reaches the muck heap.

And the more we learn about soil and nutrient cycling, the more sense that seems to make.

What’s actually happening in the bedding?

Animal manure and urine contain nitrogen compounds. As microorganisms break these down, some nitrogen becomes ammonium, NH₄⁺, which exists in a balance with gaseous ammonia, NH₃.

That balance is affected by things including pH, temperature and moisture. Under the right conditions, more nitrogen can be lost from the manure as ammonia gas.

That familiar sharp smell in a livestock building therefore isn’t simply the smell of muck. It’s also an indication that nitrogen is moving out of the manure and into the atmosphere.

From our point of view, that matters twice.

High concentrations of ammonia aren’t desirable for the animals or for the people working in the sheds, and any nitrogen that disappears into the air is nitrogen that we’re not retaining in the manure to eventually return to the land.

Of course, Bokashi isn’t a replacement for good husbandry. You still need enough dry bedding, good ventilation, sensible stocking levels and properly managed water.

But alongside those basics, we’re interested in whether we can influence the microbial conditions in the bedding itself.

So what does Bokashi Bran do?

Bokashi is based on fermentation.

Our Bokashi Bran is wheat bran inoculated with a microbial culture and fermented with molasses. We make it here at Lower Blakemere Farm in batches of around three tonnes at a time, before drying it so that the microbes remain dormant until moisture wakes them up again.

The idea is to introduce a useful microbial population into organic material and encourage fermentative processes rather than simply leaving everything to uncontrolled decomposition.

There is published research into Effective Microorganisms and other microbial treatments showing that they can influence odour and ammonia in manure, particularly in poultry systems. The exact result depends on the microbes used, moisture, temperature, bedding, livestock and overall management.

So we wouldn’t claim that sprinkling Bokashi into every livestock building produces a guaranteed percentage reduction in ammonia.

Biology is rarely that tidy.

What we do know is that microbial activity, moisture, pH, temperature and manure management all influence how manure breaks down and how much ammonia is released.

And that fits very well with what we observe ourselves.

What Farmer Phil notices

We use Bokashi regularly in our deep-litter cattle sheds, sprinkling it as we put fresh straw down.

The cattle then spend the next few weeks or months walking across the bed, gradually mixing the bran, manure, urine and straw together.

Several hundred kilos of cattle are remarkably good compost mixers.

Farmer Phil probably notices the practical difference more than anyone:

“For me the biggest difference is the atmosphere in the shed. There’s much less of that sharp ammonia smell, so it feels much fresher for us and the cattle. It’s easy because we put the Bokashi in as we bed up and the cattle do the mixing. Then when we muck out, the straw and manure have already been worked together and started breaking down. It comes out well and, by the time we’re putting it back onto the land, it has already had a really useful head start.”

— Farmer Phil, Lower Blakemere Farm

That “head start” is probably the best way of describing what we’re trying to achieve.

Bokashi doesn’t make finished compost in the shed

This is an important distinction.

Bokashi is sometimes described as making compost, but technically that’s not quite right.

Bokashi produces fermented organic material — sometimes described as pre-compost — rather than finished, mature compost.

Fermentation is an early stage in the process.

The material still needs to go into soil or move through a further composting stage where a much wider community of aerobic bacteria, fungi and other decomposers continue breaking it down and stabilising it.

So when our cattle bedding comes out of the shed, we don’t regard it as finished compost.

It hasn’t magically become mature compost simply because we added Bokashi Bran.

What it has done is begin the process.

The straw, manure and urine have been mixed, trampled, moistened, inoculated and biologically worked on before they ever leave the shed.

That is what we mean when we talk about pre-composted muck.

It’s part-way through the journey rather than starting from scratch on mucking-out day.

The cattle shed becomes Stage One

Traditionally, we might think of the process as:

Cattle shed → muck out → manure heap → composting begins.

But biologically, decomposition has obviously been happening long before the loader arrives.

In deep litter, we already have carbon from the straw, nitrogen from the manure and urine, moisture, warmth and a huge population of microorganisms.

Then we have cattle constantly mixing everything together with their feet.

By adding Bokashi Bran as the bed builds, we’re deliberately adding another microbial input to that system.

So we now tend to think of it more like:

Cattle shed → fermentation and biological breakdown → muck out → further composting → soil.

The shed itself becomes Stage One of the composting process.

How much Bokashi do we use?

We don’t make this unnecessarily complicated.

As a practical starting point, use roughly one good handful of Bokashi Bran per square metre of bedding, with a little more in particularly wet or heavily soiled areas.

Then add another light scattering whenever you put down a fresh layer of bedding.

For deep litter, the principle is really little and often.

This is our practical farm rate rather than a scientifically prescribed dose. There isn’t one universal application rate that will suit every species, building, bedding type and stocking density.

A dry hen house and a cattle shed are very different things.

So start there, watch what happens and adjust according to your own system.

It works on a smaller scale too

Although we use Bokashi in our cattle sheds, exactly the same principle can be useful for smallholders keeping chickens, ducks, goats or sheep.

With chickens, scatter it through the bedding, particularly beneath perches, around drinkers and wherever droppings accumulate. The chickens will scratch and mix it through for you.

With goats and sheep, add it as you bed up and let their feet work it into the straw.

Ducks require slightly more realism because they are extremely efficient at creating wet bedding. Bokashi won’t compensate for a permanently waterlogged shed, so water management and plenty of absorbent bedding must come first.

But the principle remains the same.

Add a small amount regularly and let the animals do most of the mixing.

Then move the material into a composting area

Once we muck out, the next stage is to allow the material to continue breaking down.

For a smallholding, that doesn’t need to mean investing in complicated machinery.

A very simple system can be made using three pallets to form the sides and back of a bay, with a tarpaulin or similar cover over the top.

Fill the bay with the bedding and manure and, if you have them, mix in other suitable organic materials such as crop residues, leaves, spent plants or vegetable matter.

Another light sprinkling of Bokashi Bran can be added as the heap is built.

Then cover the top.

The idea isn’t to seal the whole heap airtight. Once we're moving into conventional composting, oxygen becomes important and the gaps between the pallets allow some airflow.

The cover is mainly there to stop excessive rain soaking through the heap and carrying soluble nutrients away.

You want the material moist.

You don’t want it sitting in a puddle.

Then give it time.

Fermentation first, composting afterwards

This is probably the most useful way of understanding the whole system.

Bokashi fermentation and composting are not quite the same thing.

During Bokashi fermentation, microbes begin changing the organic material under relatively low-oxygen conditions.

Once that fermented material moves into a compost heap or soil, a much wider group of organisms takes over.

Aerobic bacteria, fungi and eventually all sorts of tiny soil creatures continue decomposing the organic matter.

Given the right conditions, worms may join in too.

The material becomes progressively more stable until eventually we have something much closer to the humus-rich organic matter we actually want in the soil.

So the process is:

Fresh manure and bedding → fermentation/pre-compost → further decomposition and composting → stable organic matter → soil.

That is more accurate than simply saying Bokashi “makes compost”.

And actually, we think it makes the whole process much more interesting.

Because ultimately this is about soil

We’re increasingly trying to look at everything we do here through the soil.

And one of my favourite facts about soil still takes some getting your head around:

A single teaspoon of healthy soil can contain more microorganisms than there are people on the planet.

Billions of bacteria can live alongside fungi, protozoa, nematodes and countless other organisms in an amount of soil you could balance on a teaspoon.

That extraordinary underground community is constantly decomposing organic matter, cycling nutrients and helping to build soil structure.

Which is why we increasingly question the idea of manure as something we need to “get rid of”.

It isn’t waste.

It contains carbon and nutrients that have come from the land, through the plants, through the cattle and into the bedding.

Our job is to work out how we can cycle as much of that as possible back into the soil.

Closing the loop

This is really what we’re trying to do with Bokashi in our cattle bedding.

We’re not suggesting it’s magic.

It doesn’t replace good animal husbandry.

It doesn’t instantly turn strawy muck into finished compost.

And the biology will behave slightly differently on every farm.

But it allows us to start working with that biology earlier.

We add Bokashi Bran as we bed the cattle.

The cattle trample it through the straw, manure and urine.

We notice less of the sharp ammonia smell and a fresher atmosphere in the sheds.

When we muck out, the material has already begun breaking down.

Then we allow it to compost further before returning that organic matter and fertility to the land.

So rather than thinking:

Animal → muck → waste

we’re trying to think:

Soil → plant → animal → manure → microbes → compost → soil.

It’s another small part of trying to farm in a way that closes loops rather than constantly opening new ones.

And when there can be more microorganisms in one teaspoon of healthy soil than people on the whole planet, it seems to us that working with the biology is a pretty sensible place to start.