A desire to grow milk from forage for an indoor-based, robotically milked herd saw zero grazing introduced at Oldbury Farm, Gloucestershire, three years ago.
Hannah Park found out more about how the system works...
Challenges in finding milking staff and a desire to achieve a more desirable work-life balance saw robots installed within the 150-cow all-year-round calving system at Oldbury Farm, near Arlingham, almost eight years ago.
However in struggling to balance the figures based on his original budget of 24p/litre and with numbers not stacking up, David Merrett began considering ways the farm could make cost savings.
When a continually fluctuating dairy market came to a head in 2015, he decided shifting towards driving more output from grass was the right direction to go in.
A significant investment had been made to install the two robot milking machines alongside a new 130-cow cubicle building which was put up around the same time, but the farm’s infrastructure did not conventionally lend itself to a grass-based system.
Speaking as one of the farm hosts at the recent British Grassland Society’s summer meeting tour, Mr Merrett explained: “After hearing plenty of advice on the merits of getting more output from grass, we were keen to tap into this and reduce costs.
"But the additional outlay which would have been needed to make our system work alongside grazing cows outdoors would have been significant and we also wanted to keep the flexibility when it came to crop rotations.”
After considering the options and undertaking market research, he decided to switch to a zero grazing system, which has now been in place at Oldbury for the past three years.
This saw investment in a purpose-made machine designed for zero grazing and sees an average area of 0.4ha (one acre) of grassland cut daily over the seven-month grazing season, with cutting and feed-out taking up to 45 minutes depending on the distance travelled.
Pasture is generally rested for 25 to 30 days post-cutting, with most rotations followed with a moderate fertiliser dressing depending on slurry application which is spread using a trailing shoe.
Cows currently get about 150 tonnes of fresh grass per month from mid-March to mid-October, which is fed alongside a TMR.
Within the farm’s total area spanning 70ha (172 acres), four-year temporary leys are grown in rotation with maize and wheat, with maize silage and home-grown urea-treated wheat forming part of the TMR.
Grassland is made up of about 30ha (74 acres) of high sugar grasses, alongside 6ha (15 acres) of Italian rye-grass.
Mr Merrett said: “Having a mixture of high D-value grasses and Italian rye-grass leys has worked well, particularly in extending the grazing window at the shoulders of the season with the latter.
“We are currently aiming to get 10 to 12kg/DM/day from grass into the cows, with growth rates and covers monitored by eye.”
Grass was initially cut in the early afternoon and fed out, but this has since moved to mornings which Mr Merrett found suited the system better and avoided cows ‘bingeing’ on the grass.
The herd is split into two groups for the robots, based on days in milk. He explained cows had generally adjusted well to the change in diet and introduction of grass.
Maximising output remains a focus at Oldbury, with the Holstein Friesian herd averaging a total annual milk yield per cow of 10,000 litres last year.
With just under 3,000 litres of this coming from forage, pushing this figure up will be a focus looking ahead, given that cost saving was a major driver to installing the zero grazing system.
Mr Merrett explained: “Before switching, the cows were essentially getting a winter ration all year
round, so we are probably making in the region of 400 to 500 tonnes less silage per year now.
“Forage requirement was also a consideration when costing the zero grazing system, as we had got to a point where clamps were overflowing and would have had to consider building another.
“We are looking to get to a feed rate of 0.3kg/litre and have seen savings in bought-in feed, as well as contractor costs, in not making as much silage and space to grow more of our own wheat.”
Much of the farm’s ground is also a distance from the cow building, which also suits the zero grazing system well. The furthest ground is about 20 minutes away on the tractor, which I probably would not travel to unless I was desperate.
“And we are utilising grass more efficiently – what the cows do not eat is fed to bulling heifers.”