Benefits of following maize with Westerwolds ryegrass

Including freshly cut Westerwolds ryegrass in the ration during housing is increasing daily milk yield by 2 litres a cow in a Ceredigion dairy herd and capturing significant cost savings on protein feed.

The fast-growing cover crop is established directly after the maize harvest at Tafarn-y-Bugail, near Cardigan, to prevent soil erosion and provide valuable nutrition in fields that previously remained bare before reseeding in spring.

See also: Benefits of early bite after maize for autumn-calving herd

Joining forces with Farming Connect as an Our Farms project, Dyfrig, Elin and Llyr Griffiths examined what this system was delivering for their business and for soil health.

The 2024-25 study showed multiple financial and environmental benefits from growing and zero-grazing Westerwolds.

These included an increase in milk income from the 500-cow herd by £450/day (milk price during the study was 45p/litre), following an uplift in daily production of 2 litres a cow. Average milk yield was 31 litres/day at 4% butterfat and 3.3% protein.

In addition, the cost of purchased protein included in the total mixed ration (TMR) reduced by £130/day.

Winter cover

The soil health benefits from covering maize fields with grass over the winter are obvious, Llyr observes.

He says he can easily spot a field not growing Westerwolds because of the amount of soil it loses.

“When there is heavy rain, you will see brown water running out of a gateway, and you really notice that when the field is steep.”

There are also financial benefits of using the land productively.

“There is nothing worse than seeing a field doing nothing, a bare field doesn’t pay for itself,” he points out.

“It doesn’t make sense not to grow a cover crop of grass after maize – the cost of getting the job done is nothing compared with the benefits.”

Llyr Griffiths © Debbie James

The Westerwolds ryegrass mix is direct-drilled into the maize stubble immediately after harvesting.

“We do all our own machine work, so as soon as we take the maize off, we work through the night to get the grass seed in while the ground is still dry,” Llyr explains.

This year, he expects the maize to be harvested on about 20 September.

Establishment and labour costs

The Westerwolds seed costs £50/ha and Llyr reckons it would be a further £62/ha to drill for a farm without its own kit.

He applies 125kg/ha of urea as soon as possible after the seed is sown, followed by a light layer of slurry after the first zero graze – which starts in mid-February.

Each field sown to Westerwolds is zero-grazed twice in its first season; if it is a good ley, it will be left to grow on for a second year, but if it is patchy, the field will be sown back to maize.

There is a cost associated with zero grazing – Llyr estimates it increases labour requirement by two hours/day – but the net financial benefits are significant.

A forage wagon for zero grazing set the business back just £3,000 as it was purchased second-hand.

“It does the job, and we have our own mowers and tractors,” he explains.

Growing conditions

Agronomist Lawrence Couzens, who provided expert guidance, is a keen advocate of sowing grass after maize, especially Westerwolds.

“It is cheaper to establish than other varieties and will grow at a lower temperature.

“If you get good establishment, you get one heck of a crop – if everything goes to plan, it will yield 15t/acre [37t/ha].”

The downside, he says, is that, in his opinion, it is a 12-month crop. “If you try to extend it to two years, the yield will start to diminish.”

If a farm is prone to drought, he suggests a cocksfoot and festulolium mix could be a better option.

“It all depends on the season; in 2025, there is a good chance that we will meet the time threshold for getting some remedial work done and getting the seed sown in good time for Westerwolds,” he says.

Nutritionally, Westerwolds will not match Italian ryegrass, Lawrence admits, but the seed is cheaper.

“Westerwolds is cost effective as long as you get good establishment. In an ideal world, it will need to be sown before the end of October when the soil temperature is still 10-15C.”

He advises lightly cultivating the soil after the maize has been harvested to rectify any compaction to allow water to infiltrate the soil.

Feed value

In 2025, grass at Tafarn-y-Bugail analysed at a metabolisable energy (ME) of 12MJ/kg dry matter (DM) and 24.9% crude protein. It was fed at a rate of 20kg a cow a day alongside the TMR.

This includes 4kg water in the pre-mix, 4kg bread, 18kg maize silage, 18kg grass silage, and 1.2kg rumen-protected rapeseed – down from 2.2kg before the cut-and-carry system was introduced.

Llyr says the area of maize grown on the farm will almost certainly increase.

“I can see us growing more and more maize every year; we have good soil for it and south-facing fields, and the cows are a lot more settled and content on maize.”

That will mean more Westerwolds grown, too. “I wouldn’t leave any fields without grass now,” he insists, adding that the findings of the project have reinforced his own observations.

“As farmers, we have to protect our soils, they are our most important asset.

“It makes complete sense that we shouldn’t leave any field exposed through the winter,” he says.