Case study: Keeping grass in the diet during drought at Wolfhall Farm, Wiltshire

This month, Piers Badnell, consultant at Pasture to Profit, spoke with Anthony Mitchell, herd manager for Tom Blanchard at Wolfhall Farm, a Forage for Knowledge contributor and an AHDB Strategic Dairy Farm, to see how he has been coping in the dry weather.

How much rain have you had?

I have had 125 mm so far this year with 22 mm in the last five weeks.

What are your soil types and how do they manage?

Greensand on the platform. When it’s very wet they can be bottomless, but after 3–4 days with no rain they will carry cows. When it’s dry, it dries out properly.

How would you describe the weather pattern and climate over the last few years?

Much wider conditions. Long blocks of very wet, dry, and cold weather. Just more extreme.

What is the average cover today (8 August 2025)?

It is running at 2,175 kg DM/ha.

When did you start getting dry and what was your response to it?

March

We started getting proactive around 20 March as it had been unusually dry for so long and looking at the long-range weather forecast it just carried on looking dry.

Growth was around 30 kg DM/ha but I would have expected it to be moving towards 50 kg DM/ha. I didn’t want the average cover to drop so I extended the first round to finish on 19 April.

Also, in late March I made the decision not to drop average cover to 1,950 at balance day like I normally do. Instead, we made sure it didn’t drop below 2,150. The key was maintaining average cover.

April

By 19 April, round length was 28 days. Grass increased in the diet and concentrate came out, but there was no surplus to take.

By the end of April/early May I was concerned about having enough grass to lock up for standing hay for the autumns, so we bought some hay as a safety net.

May

Through April, May and early June we were grazing 3,500 entry cover grass with an average cover of around 2,600. It’s not where we would normally be, but with no rain I needed to keep cows grass fed.

Growth rates were in the region of 55 kg DM/ha but there was still no rain, and it was getting drier. With tight allocation we were hitting residuals and trying to take care of future quality.

When we had rain in May we grazed the high covers to let the rest of the platform catch up. These were locked up for some standing hay for the autumns.

The rain came in mid-May but there was not enough. While it did give us a growth spurt up to 80–90 kg DM/ha, this didn’t last much longer than 10 days.

We kept the round length at 30–35 days as we knew the moisture wouldn’t last. The growth dropped back to 55 kg DM/ha where growth and demand matched each other.  

June

In the first three weeks of June, we pre- and post-mowed two thirds of the platform to manage heading. There was some moisture left in the soil from the rain in May due to the round length we were on, and grass was recovering.

With no rain by the end of June we were on an 80-day round length with growth at about 20 kg DM/ha. The autumns were still milking so we were under pressure until mid-July when we dried them off.

July

By mid-July we went to a 120-day round length and average cover was healthy at 2,120 kg DM/ha. Just because you are on a 120-day round that does not mean all paddocks will be fed at 120 days as the rain should come.

On the 120-day round cows were fed 5 kg DM grass, 2 kg DM rape and turnips, 6 kg concentrate and 7 kg DM silage for a 20 kg DM intake. We sat at 120 days for 18–20 days to get through the peak of the hot weather in mid-July (low 30’s).

On 26 July we dropped from a 120- to 100-day round. Then every 5 days we dropped another 20 days off the round length after receiving 15 mm of rain and dropping temperatures. This enabled a little growth of about 20 kg DM/ha matched by demand of 20 kg DM/ha.

Everything greened up a little and the recently grazed paddocks and ungrazed paddocks started to grow. This enabled us to make the most of third leaf growth, and not just growth but some quality too.

August

By early August round length was 60 days with 25 kg DM/ha growth, but the long-term weather forecast still looks dry and some high temperatures are predicted so round length will stay at 60 days for now.

Anthony says he is fine for 24 days and nights without worrying what the rest of the platform is doing.

Last week he had 7 mm and 17 mm which has been used up now but has grown some dry matter. It is key to work with the plant, with limited rain and long rounds the platform is green and ready for better rain when it comes.

Do you have concerns of a long round and stalky grass and seedheads?

Don’t worry, it’s not that bad. If you clear and clean up in late June, most of the potential problem is sorted.

Don’t forget that 1–2% of tillers head a second time but there are millions of tillers in a hectare. If you look past the odd head and stalk there is green three leaf grass at the base and any brown will rot away in the autumn.

What do you use for your decision making?

I use:

• Long-range weather forecasts
• Plate metering every 10 days
• Visual assessment of leaf appearance and how many leaves the plant has. The ryegrass plant has three live leaves and in periods of stress the leaves will be smaller. A three-leaf plant can be well under normal grazing entry cover even just 7.5–10 cm, but at three leaves it is ready to graze, so graze it

What is your conclusion on dry weather management?

Correct round length, correct average farm cover, and hit residuals!

 Anthony is having to supplement but at the time of writing he has:

• Average cover: 2,175 kg DM/ha
• Grass in diet: 8 kg DM
• Platform: Green and ready to respond when the rain comes

A conservative estimate is that it will be two to three weeks ahead and maybe four to five weeks ahead if Anthony has not extended the round early.

Grass utilisation and cost of production drive profit. Prompt action has prolonged use of grass in the diet for this business, which has enabled continued grass utilisation and minimised extra feeding costs.