Herd Homes 2009

Brett and Gayle Farrell have gone a long way towards winter proofing their Northland dairy farm business with Herd homes and have become among the first to trial a new dairy yard that doesn’t need a hose down after every milking – saving around 50 litres per cow and conserving valuable effluent for use back on the farm.

Brett and Gayle moved to their then 200 ha Drinnan Rd farm in 1993. They started off milking 206 cows they have since doubled the size of their farm and production has increased 10 fold. They have 860 cows have four fulltime staff. The farm is 310ha effective.

They are winter milking 560 cows.

The Farrell’s used to worry each winter about the comfort of the cows and tried to work out what they could do about it. In 2006, they divided their 420 cows into two mobs which took turns occupying the Herd Home day and night.

That meant the cows only had to walk to the paddocks once a day. The rate of lameness fell away and they noticed other benefits such as reduced soil compaction.

Brett says they’d be putting in more herd homes if the payout were looking healthier. He says their biggest limitation is that they have to pack the cows into the homes and the animals are in their on what amounts to “split shifts”.

He says they’ve noticed a big drop off in lame cows and the only real negative is a slightly higher incidence of mastitis – largely due he thinks to the home being a little crowded.

The Herd Homes were invented by Northland farm Tom Pow about eight years ago on his 90ha Mata farm, about 20km south of Whangarei.

Tom came up with the idea for specialised shelters when thinking about how to house his cows after long wet spells that turned his paddocks boggy. He investigated what was around in New Zealand and overseas but could not find anything that 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 airflow 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.

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.

Front-end loaders were used to lift the slats and dig out the muck that 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.

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.

The Herd Homes also keep cows warm in winter and cool in summer. 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. Tom says 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.

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. It is claimed that some of the Herd Homes had paid for themselves within three years.

There are 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.

The Herd Home “dairyard” incorporates a milking platform with a holding yard constructed along the same principles as the herd homes.

The accumulated dung is valuable fertisliser if it is kept reasonably dry. Soaked by dairy yard hose-downs it would be sloppy, smelly droppings – it’s nitrogen depleted.

On the Farrell farm there are drains in the basement of the new dairy yard and the two adjoined Herd Homes – through which the Farrells cycle their 860 cows. The drains gravity feed urine into sump from where it can flow into a trailer tank to be spread on paddocks at the rate of 3000 litres a hectare (roughly equal to 80kg of urea / ha).

Dung is spread on the farm’s 30 ha of maize paddocks at a rate of 30 tonnes to the hectare. Brett says they can grow maize exceptionally cheaply this way. Recent research by FAR on the way N is absorbed into the soil when it is delivered this way shows that he should be putting in on a lot earlier.

The concrete slats system meant less washing of the area, reducing the volume of waste water. They dairyard is claimed reduce water usage by up to 60 litres a cow.

The Farrell’s dairy yard is the first of four experimental Herd Homes dairy years to be built around the country. Agreement had to be reached with Government to allow people using the dairy years to stop hosing down after milking.

Further work is ongoing to see if the Food Safety Authority would consider whether the yard design could be approved for unrestricted commercial construction or whether further experimentation was needed to satisfy overseas dairy markets.

Brett Farrell says the capital cost is high – the new rotary shed and infrastructure cost close to $1M and the dairy yard around 250 K – but he says the new facilities were future proofing the farm environment and reducing fertiliser expenditure.

Brett says there are still teething problems with the dairy yard – runoff has to be tightly controlled because there are no drains (unlike conventional dairy yards). He says unloading the manure from beneath the yard bays is time consuming – and needs to happen anything up to 5 times a year. But he says that time is easily covered in the reduction in bought in fertiliser.

Brett is involved with Landcare. Using the dairy yard and herd homes hasn’t meant an end to effluent ponds and there’s been a few adjustments required to make sure all run-off ends up in the right place – especially when it rains. He has quite a complex effluent pond structure which ends up in a wetland. He says the contour of the farm isn’t all easy and he’s rolled his muck spreader. They do nutrient testing on a regular basis.