A Farm Effluent System Update

November 2015

Rex Butterworth has changed his effluent system with help from consultant Alison Dewes

Rex Butterworth who farms in the Waikato has spent nearly $1 million investing in HerdHomes, where his cows spend part of the day under cover feeding.

In the past 3 decades the Butterworths have significantly changed their dairy effluent system 3 times and were recently staring at another change. They decided instead to trial partially housing the cows and haven’t looked back environmentally or economically. They invested heavily in new herd homes that have cut the volume of nitrogen leaching through the soil to less than half the average in the region.

With capacity for 500 dairy cows, the homes shelter the dairy herd from wind, rain and sun while tanks below the ground collect effluent, which is stored and later used as a fertiliser for growing maize.

The system reduces wastage, heat stress, cuts down fertiliser costs and improves efficiencies.

Rex says their cows are producing about 45 per cent more milk solids, going from 1450kgs/ms/ha with a cost of production of $3.68 to 2220kgs/ms/ha with a cost of production of $3.13. They are confident that they can lower the cost of production closer to the $3 mark and estimate the system, which cost about $1875 per cow, will pay for itself within five to seven years.

He says more farmers need to invest in technology and change the way they farm in order to boost returns. “We have been farming in New Zealand virtually the same way for the last 30 to 40 years,”.

For Rex effluent was a hassle – now it’s a valuable commodity.

The farm is at Walton. It’s 106ha effective milking 485 cows. Rex has been here for the last 17 years and the current season’s production is about 10% ahead of last year.

As he became more aware of nutrient leaching, Rex started thinking about what his impact was on the land and water around him. He says the information available to help monitor this is getting better and better, putting him in a stronger position to make well informed decisions.

He looked at their production graphs and tried to find a way of evening out production levels while at the same time protecting the pasture and the environment. He says after the first season the herd homes had improved his production figures by 31% with no extra cows or feed.

Rex says in the winter a lot of what the cows eat is to maintain body temperature. In summer that works against them as the cow’s consumption drops as the ambient temperature rises. He says by bringing them into the herd home during hot summer days the cow’s temperature drops enabling them to eat and drink as they would normally.

They started with a 250 cow herd home in 2013 at a cost of about $475,000. On the basis of that first herd home, they then added another herd home to cover the whole herd. He says the cows are so much happier.

There are timed gates which allow the herd to move back into the homes when the farm staff isn’t about which is less work. There’s no daily maintenance and you don’t have to drive around the farm to feed out.

He says the herd homes have given him some confidence about “doing the right thing” in his environment. He says there are no downsides.

N leaching has dropped to 25kgs/ha and P to1.3kgs/ha and he hopes to improve further on that. He says there is no excuse for not knowing what your farm’s impact is on the environment and for not finding ways to reduce that. He explains most farmers are working hard in this space to try and minimize the impact they are having.

The animals wander into the shelters at about 3am each day to feed before milking. They then head back to the paddock for a few hours and return to the shelter when the sun is too fierce or the wind and rain too cold. In the depths of winter, when the soil is wet and the grass can’t take up the volume of nutrients released from their urine, they spend most of their time in the herd home.

The volume of nitrogen leaching from his paddocks has dropped to 40% below the regional average. By returning the collected effluent to the soil at times when it can be taken up by the growing plants, he’s saving money on artificial fertilizer, and because his pasture doesn’t get such a hammering from the cows’ hooves, the grass grows better. Because the animals are protected from the extremes of heat and cold, they are under less stress and produce more milk – his milk production has increased by 45%.

Rex sprays the collected effluent onto his maize ground, a crop that is highly efficient at turning the nutrients into fresh new growth.

“The new system is proof that if you surround yourself with the right people and have the right tools, intensive system 5 farms can operate at environmental levels well below what is achievable by most conventionally run properties, and can do it profitably on both high and low payouts. If we can do it anybody can.”