KEY POINTS:
Profits and the environment are coming up green on farms providing specialist New Zealand designed Herd Homes, keeping both cows and farmers happy.
Northland dairy farmer Tom Pow can't keep up with the demand for the Herd Homes he invented about seven years ago on his 90ha Mata farm, about 20km south of Whangarei.
"They've taken off, just gone berserk." Mr Pow, director of Herd Homes Systems, came up with the idea for specialised shelters when thinking about how to house his cows after long wet spells which turned his paddocks boggy.
"I started just planning a feed paddock for when the weather was against us, and an animal shelter."
Mr Pow investigated what was around in New Zealand and overseas but could not find anything which impressed him.
"Animal shelters date back to when people were sleeping with stock in caves and are not new to New Zealand, but dealing with the effluent has been a challenge."
He invented a system, where air flow is critical, using a roof which allowed clear light in so the excrement dried up on the concrete slat floor, minimising bacterial build-up.
"The cow muck gets pressed on to the slats ... their high-fibre diet comes through and sticks to the concrete, like a compressed cow carpet which won't wear out their hoofs."
Mr Pow said the gaps between the pre-stressed concrete slats also meant the concrete was less slippery.
The urine and dung fall into an aerated concrete bunker which allows the effluent to remain stable and relatively odour free, retaining its nutrients and keeping it in a suitable state to return to the farm.
"The fact it is not very smelly is a good sign as if you've got odour it means you are losing nitrogen and sulphur, both fertilisers which a farm needs."
Front-end loaders were used to lift the slats and dig out the muck which was then re-spread as manure on the paddocks.
"The advantage of it being quite gooey and sticky is that it's more weather tolerant and doesn't run off in a big storm ... it helps protect the natural waterways so is environmentally safer."
Mr Pow said farmers needed to dig out the manure only a couple of times a year but some farmers were excavating the dung more often as they required it.
Five of the Herd Home farms now didn't require artificial fertilisers, including his own.
Mr Pow said the Herd Homes also kept his cows warm in winter and cool in summer.
"The cows love it ... each cow produces the equivalent of a two-bar heater."
The only problem can be getting the cows out of the homes when the weather was lousy.
In summer, a shade cloth helped create thermal air currents by drawing up the hot air and allowing new air in, making a draft.
Mr Pow said the cows did not waste so much energy through panting and looking for shade.
As cows could harvest 80 per cent of their feed in a grassy paddock in a couple of hours they did not have to stay outdoors all day.
Once full, the cows would wander back to the Herd Homes where they could get extra feed and even be calved.
Mr Pow has also developed what he has named a "dairyard" which incorporates a milking platform with a holding yard constructed along the same principles as the herd homes.
The concrete slats system meant less washing of the area, reducing the volume of waste water.
"It can reduce water usage by up to 60 litres a cow."
Mr Pow said while Herd Homes were expensive, about $270,000 for a 60m-long construction to house 200 dry cows, there were savings.
In Southland, some farmers with Herd Homes were reporting up to 40 per cent savings in feed requirements because their cows were warmer and less hungry.
Mr Pow said the savings in the use of artificial fertilisers, water and power were all a bonus and farmers were getting a 20 per cent overall return on their investment.
Some of the Herd Homes had paid for themselves within three years.
"So if you can afford the capital investment it is lucrative ... the savings in manure alone cover a year's interest."
Mr Pow was working closely with AgResearch and he had patented the systems as he developed them.
There were now about 200 Herd Homes throughout New Zealand with another 100 being built this year.
The export potential was huge but he was still struggling to keep up with local demand.
Auckland born and bred, Mr Pow said he started out as a farm cadet, purchasing his first farm with his wife when he was 23.
The early converts to Herd Homes were similarly not born into conventional practices and were open to new ways of doing things, he said.
