Joining the grassland monitoring project, GrassCheckGB, and switching to paddock grazing is helping a high-yielding herd in Dorset maximise milk from grazed grass and cut its concentrate costs.

Dorset dairy producer, Josh Booth, says he’s still on a learning curve when it comes tograssland management. Still in his 20s and gradually taking over, with his brother, Michael, at Manor Farm near Dorchester, the family are keen to produce as much milk as they can from grazed grass – the farm’s cheapest feed resource.

His parents, Andrew and Vicky, had signed up to the grass monitoring project, GrassCheckGB, in 2019. So Josh aims to continue using the information the project supplies to raise the quality and increase the growth and utilisation of grass on the 243 hectare (600 acre) farm.

The 10,000 litre herd had been strip grazed until around two years ago, but the family recognised that grass utilisation was not optimised under that system.

“Utilisation was especially poor at this time of year if the weather was dry and the cows may have gone on to inadequate covers when they first went into a new field,” says Josh.“However, by the time they’d moved across the field, the grass was usually too long andstemmy and I’d say the covers were probably close to 4,000kg dry matter (DM)/ha when we moved the fence for the last time.

“The balance between grass quality and quantity wasn’t ideal, and the cows would lie on and waste a lot of the long grass,” he adds.

The family decided to move to paddock grazing, splitting the farm’s core grazing platform –which comprised four fields over 26ha (65 acre) – into 24 paddocks of just over one hectare (2.7 acres) each.

The 24 paddocks are grazed for a minimum of four hours/day by the high-yielders from the year-round calving herd, always meeting and sometimes exceeding the minimum grazing requirement from milk buyers, Waitrose.

Waitrose themselves are partners in the GrassCheckGB project, and keen to encourage their suppliers to maximise the use of grazed grass.

“GrassCheckGB ties in well with the company’s grazing pledge,” explains Brian Barnett,chairman of the Waitrose Dairy Farmers Group, who supply the supermarket’s milk. “Bysupporting the project, we are helping producers meet the minimum 120 days of grazing they commit to achieve each year, although many exceed this, at over 200 days.”

Josh confirms that the project has helped extend his herd’s grazing season, with lows out last year into November.

He uses a plate meter on a weekly basis to improve efficiency, and says: “We aim to go onto each paddock at a cover of 3,000kg DM/ha and graze it in 24-36 hours. The lows will follow the highs which have ideally taken the best quality, and we want them to graze itdown to 1,700kg DM/ha.”

A rotation length of around 24 days mirrors the number of paddocks, by which time the grass should be fully recovered for the next grazing round.

“Regrowth is so much faster under the paddock-grazing system than it was before,” he says.“I believe that’s partly due to over-grazing in some places when we were strip-grazing, especially near the gates, which perhaps left fields with residuals as low as 1,400kg DM/ha.”

Noting such low residuals tend to impede the sward’s recovery, he says grazing so low also has a detrimental effect on the herd’s performance.

The change in practice has also boosted grass production and last year, an impressive yield of 10.7t DM/ha was achieved across the grazing platform.

However, Josh says the new system is still a work in progress; paddock size may need to be adjusted and he feels too much grass went to seed in the dry spell this summer.

But he says milk production has definitely increased since the change was made, with more consistency in yields as peaks and troughs have been ironed out.

Grass quality has also improved as part of the project, with this year’s metabolisable energy(ME) levels reaching 11.6MJ/kg DM in early summer, and remaining around this level for over three months.

A further benefit of analysing grass has been in the formulation of buffer rations and Josh now sends the grass analysis results to his nutritionist, Mike Bray from Kite Consulting, every month.

Mike says: “It’s unusual, but very useful, to have this level of analysis, as we’d normally takean average analysis from spring, summer and autumn grazing, based on a previous database of samples.

“However, having the analysis allows rationing to be carried out as if changing conserved forages, and potentially makes large financial savings,” he says.

This has been quantified in the late lactation cows which have a higher reliance on grazed grass than the high yielders. When their grazed grass had just one extra megajoule (MJ) of metabolisable energy (ME) per kg DM, purchased feed costs were reduced from £1.03 to 47p per cow per day, equating to a drop from 3.27p/litre to 1.49p/litre.

Josh says: “I know we sometimes turn out on less-than-ideal leys but think that’s happenedless this year than last. I hope we will get to the stage when we are less reliant on our silagestocks and can maximise milk from grazed grass.”

Manor Farm facts

  • 275 milking cows produce 10,000 litres on 243ha arable and grassland farm
  • Joined GrassCheckGB in 2019; moved from strip- to paddock-grazing system
  • Aim to enter covers at 3,000kg DM/ha and leave residuals of 1,700kg DM/ha
  • Analyse fresh grass fortnightly, aiming for high ME
  •  ME maintained through spring and early summer but dropped in August
  • Declining energy was associated with grass heading in earlier summer drought
  • Reseed 26ha grazing platform every five years with ryegrass/white clover mix