Measuring grass covers weekly is pivotal to exploiting milk production from grazed grass on one of the driest farms in Wales.

Maesllwch Home Farm in the Wye Valley is lucky to get 860mm (34 inches) of rain in a year but with excellent grass management dairy farmer Andrew Giles and his team are growing an average of 13tDM/ha a year and producing 5,795 litres/cow of milk sold from a concentrate input of just 800kg/cow.

Mr Giles, who shares his grass growth data through the Farming Connect Welsh Pasture Project, says this information helps the business to plan for pinch points in the growing season, and to manage the situation at the earliest opportunity.

“The minute growth rate drops below what we would deem to be average for that time of year, especially if there is no rain in the forecast, we start to put things in place.

“First of all it would be to extend the grazing round length and, if we are going into a dry spell, we would initially increase concentrate feeding and, if needs be, feed silage in the paddock on top of a fresh break to adjust grass demand.’’

In that situation, all paddocks are brought into the rotation and silage cutting delayed.

This combination of steps is important because it can make a “massive difference’’ to the effect that drought has on grass availability and milk yield, he says.

At 2300kgDM/ha through the main growing season, the average farm cover is slightly higher that the level mostly associated with dairy grazing systems to help retain soil moisture.

An autumn rotation planner is key to hitting good opening covers and to reducing reliance on purchased fertiliser requirements in the spring.

Mr Giles says 2021 has been a good indicator of how important that planner is.

“We started off with extremely good August growth, at a time when we would normally be putting in silage to build covers, but when we got to early September, when there hadn’t been rain for a while, our projected 60kg DM/ha growth dropped by about 30kgDM, and that had an effect on the autumn planner.’’

Extra silage was fed to manage this.

“If you can see a grass shortage coming, by measuring and having that data, you can manage the situation,’’ says Mr Giles.

“It would be really difficult to manage autumn grazing and to be confident that there would be enough grass in the spring if we didn’t use a rotation planner.’’

He aims for relatively high closing covers of 2350-2400kgDM/ha because, as well as being dry, the farm experiences cold winter conditions; in 2021, cows were housed by day on October 16 and will be fully housed on November 23.

“When we first moved to Glasbury from Pembrokeshire we were using the closing cover figures we would have applied there but, because the conditions are very different here, we found we didn’t have enough grass in the spring so we needed to fine tune our feed budgeting plan,’’ says Mr Giles.

The first paddocks to graze in the spring have opening covers of 3500kgDM/ha but the average farm cover is a minimum of 2200kgDM/ha.

“High covers will over-winter well provided you have good cleanout in the autumn, we then have fresh, green swards, not dead material,’’ says Mr Giles.

Fertiliser is applied at a rate of 190kg/ha/year.

The herd calves over 11 weeks from the last week of January; turnout by day comes once 30 animals have calved.

Each 3-6ha paddock averages 10-11 grazings a year; the farm mostly hits ‘magic day’ in the first week of April.

Silage and concentrates are used to make up grazing shortfalls – concentrates are fed at a rate of 800kg/cow/year; purchased grain is milled by a mobile mill and mixed with rape meal and minerals. In 2020, this worked out at an average price of £160/t.

Mr Giles became a Welsh Pasture Project monitor farm because he has built a successful business from the sharing of information and ideas and wanted to give others a similar opportunity.

“I wanted to give something back to an industry which has served me very well, to encourage more people to look at what we are doing are farmers, and to consider if this industry would be for them.’’