Dairy farming in a drought – tips from New Zealand

Dairy farmers need to look Down Under to find new ways of dealing with extreme weather events.

That is because New Zealand and Australia are two of the world’s most drought-prone countries that still have outdoor milk production systems, says Promar International farm consultancy manager Teaghan Tayler.

Teaghan now manages a 300-cow, 5,000-litre, spring-block calving herd with her husband, Gregg, in Shropshire.

See also: Plan now for prospect of summer drought, farmers urged

Having already experienced three summers with a drought since moving to England in 2018, Teaghan believes that prolonged dry spells (alternating with flooding in some areas) could become routine for many dairy farms.

She is using knowledge gathered in New Zealand to secure feed supplies at home and implement strategies to reduce heat stress in cows.

“As a farmer, DairyNZ and Dairy Australia [see “Dealing with drought: further reading”] are my go-to resources. A lot of the advice is usable over here,” she says.

Teaghan and Gregg operate a low-cost system based around rotational grazing on 115ha (284 acres), and only feeding concentrates for the first four weeks of lactation.

Calving is timed to match grass growth.

Drought cost

Last year’s dry spell lasted from June until October and Teaghan says it cost their organic business an extra 568kg of feed a milking cow.

“We usually budget for 500kg a cow of supplement [forage and concentrates] for the whole year. In 2022, we fed more than 1t a cow,” she points out.

“We aim to grow 10-12t [dry matter] DM/ha of grass; last year we were closer to 7.5t DM/ha.”

Unfortunately, drought was followed by a winter where half of the outwintering 18ha (44-acre) kale crop was damaged by frost, then a wet spring with poor grass growth.

It meant buying in 250 bales at £45-£47.50 each.

This unexpected expense prompted Teaghan to review production costs against break-even milk price. She concluded they needed to be more self-sufficient.

“When you have to buy in forage, it’s someone else’s quality and we’d rather control that by [feeding] our own silage. This year, we are really focusing on securing our feed supply,” she explains.

To cope with a shortage of grass in early spring, the start of calving has been pushed back three weeks. From 2024, calving will start on 22 February to try to match the farm’s grass growth curve.

To grow more silage, they have rented an additional 45ha (111 acres) on a long-term basis and are targeting an 800t maize harvest from their owned land.

“We have also installed dirty water irrigation and can reach 25% of the platform and target our best-performing paddocks in summer, so we will extend this to reach more paddocks,” she adds.

Long term, Teaghan thinks they will need to look at planting diverse swards: grasses and herbs with deeper tap roots and more drought resistance for grazing, possibly with lucerne for silage.

Priorities for action

Last year, to cope with high temperatures and heat stress, Teaghan relied on best practice from New Zealand, targeting, in order of priority:

• Dirty water application
• Feed stocks
• Cull cows.

“We meet weekly after the pasture walk and have seven-day plans and long-term ones. We make a grazing plan and work out if we need to buy feed in.

“Also, we have to be aware that you are still in a drought two to three weeks after it rains. It takes that long for grazing to recover, so plan for enough feed coming out of the drought.”

But she is clear that good decisions and workable plans should only be based on reliable data and will be individual to the farm and system. Her advice is to:

• Monitor temperatures and rainfall to track weather events on your farm
• Measure grass growth
• Use soil and slurry analyses to target nutrients accurately for efficient growth.

Herd data can be analysed to select cows for emergency culling, instead of making a snap decision, says Teaghan.

They culled an extra 20 cows last year – and before the end of lactation. This helped reduce stocking rate and feed demand on the milking platform.

“We culled low-hanging fruit: cows that were empty, had high cell counts, more than one incidence of lameness and those not milking on all four quarters; then lowest yield.

“Our Johne’s cows went before the end of the season. If you don’t know, you can’t choose which cows to cull,” she explains.

Milking frequency

Cows were also put onto 16-hour milkings: “This meant we had one in the middle of the day when it was hot, but two milkings when it was cooler.

“It reduced the frequency, cut down on walking and also time spent in the collecting yard. It really reduced heat stress and it’s something we would do again.”

She adds that, in New Zealand, it is common practice to milk at 5am and then again at 6pm on hot days.

“If you know that you have two days or two weeks of hot weather coming up, you could look at changing milking times, but if it’s going to be 28C for a month, look at other options.”

When the temperature hits 40C, NZ dairy farmers switch to once-a-day (OAD) milking until peak heat is past.

“It is a trade-off, however, as you can get higher cell counts and more mastitis. But it is better than losing cows in the parlour to heat stress.

“In our experience, you can switch to OAD for one to two weeks then return to twice a day without any major long-term impacts on production,” she says.

Sharing the load

Drought strategies must be written down and explained to the farm team. Moreover, staff need to be trained in the risks to cow welfare from heat stress, says Teaghan.

She also advises seeking help. “Any farmer [dealing with drought] needs to reach out to their trusted advisers – whether that’s a neighbour or consultant.

“There isn’t one size fits all and it’s good to get a different perspective on a problem, because it’s easy to go down a dark tunnel and get really down.”