How herbal leys are benefiting an upland lamb finisher

Introducing herbal leys for finishing lambs has helped one Welsh upland farm improve weight gains while reducing nitrogen and wormer.

Lambs from the 480-ewe Welsh Improved flock at Esgairllaethdy, a 63ha holding at Myddfai, near Llandovery in Carmarthenshire, had traditionally been fattened on perennial ryegrass.

The leys performed poorly during recent hot summers so farmer Hywel Morgan sought an alternative that could overcome drought and would not require large amounts of fertiliser.

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He had visited farms growing herbal leys as part of a Farming Connect Management Exchange Programme study.

As a result, this year he planted 3ha of herbal leys, a diverse range of plants containing a mixture of grasses, legumes and herbs. 

They draw up nutrients from the ground with their deep roots, fixing nitrogen and providing nutritional benefits for the animals that eat them.

Farm facts

  • Farm extends to 63ha, including 8ha of woodland
  • An additional 8ha is rented
  • 480-ewe Improved Welsh ewes with a small number of Romneys. Using Welsh and Aberfield tups on these.
  • Lambing outdoors starting in April
  • Lambs mainly sold liveweight at Kidwelly Market and some sold direct
  • Grazing rights for 400 sheep on Mynydd Du, a large expanse of common land in the Brecon Beacons National Park; Mr Morgan has a licence to graze cattle there also
  • Herd of 49 Hereford-cross and Highland suckler cows
  • 3ha of swedes and 1.6ha of turnips grown as winter feed for ewes


Two leys were sown, one for grazing and the other to provide one crop of silage before grazing.

The mixes contained 17 different varieties, including lucerne, plantain, birdsfoot trefoil, chicory, sheep’s parsley, yarrow, clover and sainfoin, in varying quantities and each with specific qualities.

Mr Morgan sowed two fields with herbal leys, one in April for the silage that followed a crop of swedes and the second in May for grazing in a south-facing field with a rocky soil base; this field is part of a 10ha rotation used for fattening lambs. The two fields combined are 3.2 hectares (8 acres).

Farmyard manure was applied prior to cultivation. “Together with the nutrients from the sheep that had grazed the swedes there was no need to add any bagged fertiliser,’’ says Mr Morgan, who farms with his parents, Eynon and Eryl.

A rotavator was used to cultivate the top two inches of soil and 5t/ha of lime was applied. The seed was broadcast at 32.50kg/ha and the field rolled twice. No chemical weed control was used.

At £208/ha, the seed costs around £50/ha more than perennial ryegrass but Mr Morgan says that when balanced with the reduction in nitrogen inputs and parasite controls it is cheaper to grow.


The crop was cut on 1 August and yielded 12.5 bales/ha. After a week of regrowth, Mr Morgan turned the lambs onto it to graze.

The silage will be fed to ewes this winter.

“I didn’t want to use glyphosate to spray off the field and we did get a bit of chickweed coming through, but that can be a problem even when you spray,’’ says Mr Morgan.

Hywel Morgan at Esgairllaethdy


Two hundred lambs at an average weight of 26kg were turned onto the ley at the end of June. The field was grazed to a 10cm residual. From then on, it was grazed every other week until 20 October.

“They were being selective with what they ate in the first few days and we didn’t want them to take a dive in condition so we provided grass too,’’ Mr Morgan explains.

“They got a taste for the herbal ley after a few days and they were fine, although they do tend to take the best bits and leave the plantain until last.’’

A runback onto permanent pasture allowed the lambs to adjust to the crop. This is vitally important, as Mr Morgan learned to his cost when he lost six prime lambs to red gut during a period of high rainfall in October.

“We had kept a new bunch of lambs on the herbal leys for a little bit too long with no runback. It was my first year on this system and I didn’t spot the symptoms soon enough,’’ he says.

“I learned the hard way that it is essential that sheep have access to grass pastures at the same time so they can choose a combination of legume and grass.’’

Weight gains

Lambs achieved average daily liveweight gains (dlwg) of 200g through to finishing, with some lambs achieving gains of 300g.

“I was very pleased with the weight gains of the lambs. Some legumes and herb species provide higher feeding value than perennial ryegrass and, although we have white clover to increase the feeding value of ryegrass, it is difficult to maintain a sufficient percentage of white clover when lambs are being grazed for finishing.’’

The field tends to burn off in the summer but the herbal ley performed fantastically well throughout very dry weather, Mr Morgan reports.

“It grew back quickly – the lambs were back on it within a week [after first grazing] – and they were not so selective second time around.’’

Other benefits

As a result of growing herbal leys and making other management changes, including reducing sheep numbers by 60, Mr Morgan has reduced nitrogen use across the farm from 16t to 7t.

This year’s lambs were only dosed twice for worms – in April and August – based on the results of faecal egg counts (FECs). Evidence suggests sainfoin, birdsfoot trefoil and chicory are natural wormers.

The herbal leys have also helped to reduce water run-off from the fields; during heavy downpours, this has resulted in a slower flow of water in the nearby stream.

The leys should be productive for four years, although some mixes can last longer.

Mr Morgan sees a future where herbal leys will become more commonplace.

“I had a conversation with a policy maker from the Welsh government about farm support after Brexit. He said we would need to farm more with nature than against it.

“Over the years my father had questioned why I wasn’t using cocksfoot, timothy and other herbs that grow at different times of the year because if you look at the base of the swards in grass fields there are lots of gaps. I didn’t listen to him, but, as ever, he was right.’’