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Composting mootels (barns) are the exciting technology that can transform New Zealand dairy by addressing environmental issues, enhancing animal welfare, and increasing the efficiency of pastoral dairy

Composting mootels (barns) are the exciting technology that can transform New Zealand dairy by addressing environmental issues, enhancing animal welfare, and increasing the efficiency of pastoral dairy
Cows at rest in the Allcock composting mootel

Some readers will know that I have been writing about composting mootels for the last three years. I have been suggesting that these mootels can transform New Zealand dairy. I remain of that perspective, but only if we get things right.

When I first wrote about ‘composting mootels’, I referred to them as ‘composting barns’. Subsequently, I have stepped back from using the term ‘barn’ because it was leading to misunderstandings. For many folk in the New Zealand dairy industry, the word ‘barn’ is like the mythical red rag to the bull.   

Composting mootels are like no other type of barn. They are open structures that focus on cow comfort. Cows love them. They can be a great enhancement to animal welfare. There is minimal smell – very different to most barns.They can fit seamlessly into New Zealand pastoral systems and in the process solve key environmental problems.

I first envisaged the potential for composting mootels when I saw two of them in high-rainfall Western Oregon, in country every bit as wet as the New Zealand West Coast. I figured if they could make the composting process work there, then so could we in New Zealand.

When I returned to New Zealand, I quickly became aware through Waikato veterinarian and farm consultant Sue Macky that there was already a successful composting mootel in the Waikato on the Allcock family farm. Since then I have visited Tony, Fran and Lucas Allcock at least fifteen times and also pointed many farmers in their direction.  

On my first visit it was a miserable winter’s day and my gumboot-clad feet were more than a little cold on arrival. After standing on the cow bedding for a few minutes my feet were warm again. The reason was simple: the combination of piss and poo that the cows were depositing was composting beautifully in combination with the bedding.

The simple message is that if the infrastructure and management are correct, then the poo soon disappears and the water in the urine evaporates up through the roof-venting system. Hence, the cows have a lovely warm and dry bed to lie on. Dig down 30cm and the temperature is around 50°C. We have even recorded it to 60°C. On the surface where the cows lie, it is 35-40 °C. It’s cow bliss!

I have also learned over the intervening years that there are people who are not getting it right. This last winter I have been contacted by several farming groups who have been puzzled as to why they are not getting the necessary heat in the compost.  My standard response is to send me some photographs showing the design. The problems often start right there.

There can also be issues with management. As Sue Macky points out, if you want the composting mootel to be successful, then you need to start tilling it right from the start and if a problem develops, then you have to be on to it straight away. Once compost dies it won’t come back to life by itself.

The Allcock composting mootel is now into its seventh year. I see the animal performance figures and I see the accounts, so I know it is working. I also have the pleasure of nice warm feet when I am in the mootel talking to the cows to see what they think.

Rainfall at the Allcock’s farm can be anywhere between 1200 mm and 2000 mm per annum. It has worked in all of those years.

Fran Allcock tells a delightful story as to the thinking behind their mootel. Fran figured that the humans had a nice house to live in, the hens had a henhouse, and the dog had a kennel, but the poor cows that were earning all the money had to live outside in the mud and the rain. So Fran decided, and then convinced Tony and Lucas, that they should build a house for the cows.

Fran searched around on the internet and came up with a specific design focusing on cow comfort. The word ‘mootel’ also comes from Fran.

 At the outset, the Allcocks did not expect that the bedding in the mootel would compost. That was a bonus and it was a huge bonus. It means that the bedding only has to be changed once a year.

With hindsight, the Allcocks would make some design changes if they were starting again.The inverted V-shaped roof would have a higher pitch and the venting system and shelter cap on top of the vent would be constructed somewhat differently. Perhaps the bedding would also be a little deeper. Despite those limitations, it is the Allcocks to whom I always send prospective mootel farmers. Fortunately, the Allcocks are always welcoming of visitors.

There are other designs of composting barn that sometimes work and sometimes don’t, depending on the specifics of the design and the location. We might therefore need to be more specific in future referring specifically to an ‘Allcock composting mootel’.

Lucas tells a story how once he went into the mootel to fetch the cows for milking, but one cow stayed behind lying prone. Feeling gutted that somehow it had died, Lucas was greatly relieved to see an ear twitch. A gentle tap on the rump and the cow sprung to life, having been in a deep sleep.  I don’t ever recall a cow sleeping like that in a paddock.

The key reason that mootels can be transformational is that they provide a mechanism to solve the leaching problem from urine nitrogen, and to do so within a pastoral grazing system. The cows still go out to graze every day but then they come back into the mootel to do their resting, pissing and pooing. The compost, which is replaced once per year, is then used as fertiliser. The nitrogen is bound within the compost and is released at a rate that the grass can use rather than being leached.

What we also know is that happy warm cows need considerably less energy for maintenance in the winter, and pastures grow much more quickly when not turned into a winter mud-bath. It is a case of getting cows out to have a feed and then getting them back into the mootel. They can also be fed within the mootel.  On hot summer days, the mootel also provides shade from the midday sun.

Tony Allcock and cows inspecting the compost.

The other question I get regularly asked is about greenhouse gases. There is also good news there.

I am confident that the release of nitrous oxide (N2O) will be less in these systems than in current grazing systems. The issue of the methane that the cows burp up is going to be more challenging, but colleagues are exploring options for transforming it into much more benign carbon dioxide as it exits the barn.

There is still lots of work to be done in understanding the nuances of composting mootels and in the optimisation of associated farming systems. Accordingly, I do get a little grumpy when some members of the research and development (R&D) community are quick to criticise from a position of ignorance.  Composting mootels require new ways of thinking, and for some people that can be challenging. There is some inertia to be overcome.

*Keith Woodford was Professor of Farm Management and Agribusiness at Lincoln University for 15 years through to 2015. He is now Principal Consultant at AgriFood Systems Ltd. His articles are archived at You can contact him directly here.

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Makes sense for the West coast aka wet coast

Flying high,
Not only the West Coast. Relevant to anywhere that has a N leaching problem and that is most of NZ. Also, winter mud and pugging is a widespread issue across NZ.

Flying high,
Not only the West Coast. Relevant to anywhere that has a N leaching problem and that is most of NZ. Also, winter mud and pugging is a widespread issue across NZ.

Admittedly it does sound good, most farms unfortunately have a lack of trees and shelter during weather extremes.
Can you provide some size requirements and capital costings for say a 250 cow farm. Thank you

And they're fed with?

Pasture fed, walking too it, not cut and carry.

In NZ the most important feed will be grass as it always has been - I thought I explained that. But NZ dairy farmers already have to rely on additional feed for winter or the cows would go very hungry. Depending on region, this can be (and already is) forage crops, silage, and a range of other feeds. However, if cows are spending the night and much of the day in a composting mootel, then their maintenace requirements in winter are considerably lower. Also, utilisation and hence efficiency of supplements fed in the mootel is much higher than if fed outside in the mud and the rain.

Keith - interesting stuff. Coming from the UK, the issues surrounding housed cattle as as bad as those for out wintered cattle. Certainly an interesting alternative and worthy of further research. A couple of Qs if I may:
What is the original composition of the bedding?
Any impact on udder health - SSCs etc.?
Also, must be some N2O content to the gas given the it is derived from composting, any option for capture to put to use?

I agree that issues with housed cattle can be severe, but these composting structures are very different.
On the Allcock farm their preferred material is sawdust and wood shavings. There are other alternatives such as Miscanthus. Finely cut woodchip can also be OK but needs to be fine. Different bedding materials need dfferent tillage systems.
SSC's at the Allcocks are typically around 100 - well below average for NZ farms.
Udder health is very good and the cows come into the shed with clean dry teats. But it is important to have high temperatures in the bedding and for the composting to be aerobic.
Unlike freestall barns there is minimal release of ammonia. The N is bound to the carbon in the compost, with this subsequently used as fertiliser.
The results at the Allcocks - now into their seventh year - demonstrate the robustness of the system. But when farmers fail to follow the 'recipe' or don't understand the underlying principles then things can go wrong. And that is why we need a big RD&E programme.

I have had a couple of experiences with barns. When i was young I worked in Canada and we had 300 cows in a lean-to barn , the cows got scraps from the grain lots of seconds with silage, round bales of straw rolled out for bedding. The ground was frozen, bedding spread on farm. Today they have nearly 3000 cows less grain crops and all cows are outside as they don't get the heavy snow storms. Angus cows well fed survive fine, if they get snow they push it up to make wind breaks. They feed the cattle lots, they have muck wagons.

In the UK I went to stay with my in-laws and the local farmer decided it was a perfect time for him to have a holiday, so I ran his farm for a couple of weeks, which involved cattle in two barns. I dropped a couple of round bales of straw over the wall and the cattle had a ball pushing it around and spreading it out to sleep on, then hay and baleage. Steers were a lot of fun as crazy quiet, like pets, brother in law in UK now break feeds as he used to do with me in NZ.

In France my friend supplies feed to local dairy farm including straw, he gets paid in muck and has a spreader he borrows. He works out what his straw is worth, negotiates with the dairy farm over how many tonnes of muck he gets back. His soils love that old bedding, it's worked out well for them both.

I am really interested in this concept, just worry about costs, It would be such a nice way to farm on a horrible day. My problem is NZ already has a high cost structure. Perhaps this would be a better use of taxpayer money than bailing out the Warehouse etc, could we do it via depreciation?

Not having to muck out is a big advantage of the composting mootel.
I am confident they can be economic but finance availability is a big issue for farmers who are already high in debt.

I Canada by the end of winter the cows were hitting their heads on the roof, in the UK it was about 5 foot deep.

Interesting stuff, if I could talk the guy down the road into it, I could become a support farm which would suit me well.

If we want to be competitive with the rest of the world from a price and environment point of view the only way we can afford further capital spend such as the moootel system is via incentives to change e.g. higher depreciation rates for new capital structures such as the moootel system or incentivised riparian margin and wetland planting via new subdivision re lifestyle blocks or TDR's (transferable development rights). By doing it this way the farmer has a way to pay for the huge capital costs of the change the current govt is forcing on us e.g. drain fencing offsetting, reduced stocking rates, N loss, sediment etc etc

Keith _ I came across something similar in the 80's. A pig farmer had a modern, all concrete house , hosed out every day, for his pigs, but they wouldn't do. So he filled the pens to about a metre deep with sawdust , and the pigs did very well. After each batch was sent away the sawdust was spread on nearby land and the pens refilled with fresh sawdust. The key thing was to have sufficient sawdust to absorb all the effluent.

wee willy winkie'
With composting barns one of the keys is to till the compost daily to ensure composting is aerobic. If the system is set up properly, then the water in the urine all evaporates and exits throgh the roof vent. hence the bedding should only need to be replaced once per year. But if the infrastructure is not right - for example the preferred structure has an inverted V roof at aboout 18 degrees with roof venting andthis is important - then the evaporated water is likely to condense and produce an internal rain shower. And that is not at all good!!

In Nepal,the family house is on top of the barn, to take advantage of the rising heat in winter.

I was in the mountains of Nepal many years ago and saw those systems. There would also be a hole in the floor on the level where the humans lived that served the purpose of getting rid of the human effluent down to where the cattle lived. My recollection is that it could all be a bit smelly, whereas that is not an issue with a composting mootel that is set up properly and managed efficiently.

I guess the cows would learn not to sleep under that hole! I was there around 25 years ago, but I doubt they have changed the system much since. . It didnt smell any more than the normal village house setup, there been little plumbed sewage outside the main cities.

Oh how the years go by! It was 43 years ago that I was there climbing mountains.

You have to wonder what you could do with grasses if the paddocks only had to support feeding, as opposed to actual standing herds.

Keith, is the biggest thing holding more of these being built the cost? My guess is that barn cost a good chunk of a million dollars to set up?

Or does production go up enough to cover that cost?

Gotta be great in the southern parts of the country over winter, can't imagine a cow on a bleak day in Gore choosing to go outside over the inside option.

Cost per cow will be between $1500 and $3000 depending on the situation. The barn structure itself should be around $1500 per cow. This compares to free stall barns costing $3000 - $6000, once again on the basis of all-up cost for the total system.
Yes, this can definitely be economic, but there is a finance availability issue for farms that are high debt and with banks ultra cautious.

So, Keith, doing some basic costing, at the higher cost end of $3K/cow, then assuming:

  • Per cow production per annum is 400KgMS
  • Revenue (gross) per KgMS is $6.50
  • FWE averages out at $4/KgMS

then there is $2.50/KgMS left for everything else including tax, interest and capital repayment, drawings etc. That's $1K/year/cow. Assuming there's debt there already, it does not feel like much in kitty for the interest and repayments inherent in a Mootel capex spend. It would be Interesting to do an article with some real-life averages, to give some economic context to the Mootel configuration.

I am always cautious of generic costing exercises as the specifics can vary so much. In the case of the Allcocks, they have achieved considerably increased production of both pasture and milk and their overheads are now spread over much greater milksolids. Their production per cow has increased remarkably and hence, amongst other things, their milking labour perkg milksolids has reduced. Overall cow numbers are essentially unchanged. Fertiliser requirements are down considerably. They now produce considerable amounts of maize silage which is fed in the shed and this is working very nicely as part of the overall system change. Animal condition is excellent and this is refected with low dry rates and hence low replacement rates and excellent longevity. The accounts indicate that profitability is now considerably increased. My assessment is that it has also set them up very nicely to manage the succession issue to the next generation. But every situation is different. For example, I am currently working with a farmer where the composting barn will be what provides the social licence to keep farming, through control of otherwise unacceptable leaching. And with another farmer, it is going to be the ability to get the cows out of the mud and the rain particularly in winter, and thereby greatly reduce the human stress.

For sure, YMMV, but exactly this sort of data, with provenance, is what could advance the cause amongst the Interested but as yet Unconvinced. To use an agricultural metaphor, chicken/egg......

So KgMS/cow and hence top-line revenue up, FWE down, N leaching down, bought-in feed down, cow condition stable or up - these are the sorts of outcomes that, once quantified, bring smiles to accountants and bankers.

The dream outcome for a mootel would be the methane captured and converted to electricity to power the milking shed. There probably wouldn't be enough for it to work, though.

It is more likely we can transform it to CO2 using bugs than use it for electricity. But time will tell

If you want biogas/electricity go for the cow mattress free stall barn system which flushes out 4x day. No need to maintain compost and you can run a biogas genset. Most suited to a cut and carry/irrigation system.

Most of the methane is burped up by the cow. Existing technology cannot capture this in a free-stall system. Biogas systems capture gases produced by effluent fermentation.

This arrangement would make it easier to feed pasture-fed cows an effective dose of methane-reducing seaweed also. Otherwise they'd only have one-two opportunities to be fed it (depending on how many times a day they're milked)

This season , I put only put down 50mm of bedding in the calf pens , instead of the usual 150 -200 mm.
My thinking was i would add another 50mm each week to cover the poo etc, hence it would be cleaner.
It hasnt worked, the smell is worst, and it gets quite damp in places. It would seem the 200mm layer allows for some composting activity, which help to deal with the effluent.

Composting in calf pens seems to be quite limited. Probably because there is normally no tilling and so it is not aerobic.
I know a number of farmers in Canterbury who have been using Miscanthus for their calf pens and most of those think it is an improvement over woodchip. We need to work on increasing the supply of Miscanthus. Where are you located?

Paeroa. One year i put fairly fresh mulch under the woodchip . and that seemed to help.

Keith, how is the compost tilled each day? I'm assuming this must be when the cows are outside.

Speaking of which, do they naturally go outside by themselves each day? Or are they made to?

By tractor. Specific tilling equipment depends on the type of bedding. For sawdust and wood shavings should be grubber type. There are some situations where rotary tilling is appropriate but not for sawdust or wood shavings - it leads to the compost becoming dense and dieing
There is a photo here showing compost subsequent to tilling.
Tilling can create lots of steam if composting process is working correctly.
Tilling normally done when cows are out in paddock or being tilled but I have seen tilling occurring when cows are present in an Oregon robot milking system where most of the cows are always present.

The cows are fundamentally drivn by desire to eat - they will go wherever they think there is nice feed to eat.
That can be mediated by comfort - including the wish to be milked once the udder is full, and get out of the rain and wind. Cows don't mind the cold if they are dry and sheltered from wind. But they don't like the hot sun. Cows lie down a lot less on hard surfaces than soft surfaces - on comfortable surfaces they will lie down for at least 8 hours per 24 hour day. If they are lying down for less tha this then they are under some stress and then other things start going wrong.

Hi Keith. This sounds like a fantastic win/win/win. And you are a man who obviously knows a lot of people in the farming sector. I would have thought some universities (eg Waikato, Massey, Lincoln) might be keen to undertake research projects and report on their findings, which might help relevant government agencies and/or private enterprise to come up with their own reports and perhaps partner-up with companies that are keen to make a buck out of it. Dare I say it, but if the Greens get back in (which appears likely) could this be something that they would back (and possibly even subsidise)? I would have thought it would (due to the favourable impact on the animals and environment) but you never know. Labour's leader might also back it. Political support at that level would be valuable. Perhaps you could send your article to James Shaw and Jacinda...

One of the challenges is that the R&D organisations are all driven by money and funding. So it will require a Govt agency to get excited about it. And getting a project funded in itself takes a lot of effort and time, especially when it is outside the mainstream paradigms rather than being a marginal shift or extension to the accepted wisdom. Actually I did take one influential Cabinet Minister to the Allcocks more than a year ago and I believe he understood very clearly the potential. But subsequently both he and I have been distracted by other issues. When speakng to R&D organisations - for example universities and Crown Research Insitutions - one quickly learns that junior staff can be passionate but the senior staff are driven by funding issues. At times this can be very explicit. For example I have had the explicit phrase 'show me the money' tossed at me. Currently, I have an application to an agency for a small grant that would allow me to allocate the necessary time to pull together into a comprehensive document everything I think we know about composting mootels - both in NZ and overseas - and also to lay out the components of a comprehensive research project. I am awaiting news on that application. We need to remember that we have spent 100 years and many hundreds of millions of dollars on R&D for our present systems and a comprehensive programme on all of the various components will require a multi-agency approach. Being an optimist by nature, I remain hopeful. But I also know that the idea of composting mootels is sufficiently revolutionary that some people with influence do not even want to start listening. I hope that articles that I write - such as this one - chip away at some of that inherent conservatism.

Keith what's an alternative to using maize that would get the same overall results at the same costs? In the deep South you don't have access to large scale maize supplies like you do in the North.
MPI and Dairy NZ have partnered to look at options of alternative winter grazing, using the Southern Dairy Hub to do the research, but it doesn't involve covered structures.
Composting barns maybe a useful tool in the tool box of options for some farmers, but it won't be the only one.

Casual Observer,
Just as now, fodder and forage crops, silage ,PKE and grain can all be in the mix.
The Southern Dairy Hub will find out the hard way that the uncovered structures still involve most of the cost but the outcomes are far inferior.