Sheep special: Meeting the challenge of finishing organic lambs without concentrates

Targets

The first focus to meeting these targets is maintaining the condition of ewes, considered essential in giving the lambs the best possible start.

Mr Ridley says: “Sheep in good condition can cope better with whatever situation they face, including the weather.

“We certainly do not want lean sheep in late pregnancy as you cannot put weight on them after that, when they are putting everything into their lambs.”

As such, he has fine-tuned his system, moving ewes from grazed grass on to high quality silage through winter, as conditions dictate.

“The ewes will be out on silage from tupping, depending on the weather and the amount of grass. This winter we switched to silage later, about mid-December, because we had plenty of autumn grazing.”

The key to maintaining their condition during pregnancy is presenting them with quality, palatable silage which ewes will eat in quantity and with ease.

Mr Ridley says: “We used to treat silage as belly-fill and made it from old pastures and into big bales. But the sheep did not use it efficiently, rushing for it when it was brought out, spending a lot of time clambering on top of bales to pull out silage, and probably using lots of energy in the process.”

Since then he has switched to short-chopped clamp silage, but he has spent several years searching for the most effective method of preservation which conforms to organic standards.

“I wanted to use the type of salts-based preservative we know gives a stable fermentation but we were unable to use this under an organic system. So, we continued to try several bacterial inoculants which are organic-approved but, unfortunately, they tended to give us disappointing results.

“The silage would often heat up, some had mould at the surface and there was usually some rejection by the stock.”

Having exhausted many options, Mr Ridley was advised to try an inoculant containing a specific strain of lactobacillus plantarum in combination with an organically certified, fermentable precursor which produces powerful yeast and mould inhibitors and improves the aerobic stability of silage.

Michael Carpenter, northern area sales manager for forage preservation specialist Kelvin Cave, says: “As a homofermentive bacteria, L.plantarum converts sugar to lactic acid, which is the strongest fermentation acid.

Protein

This results in a rapid drop in the silage pH which has been proven to ensure maximum retention of true protein and energy.

“It is important to note this is in contrast to heterofermentative inoculants which ferment sugars in a far more inefficient way, producing water and carbon dioxide as by-products, a process completely avoided with this new fermentation pathway.”

The result, according to Mr Ridley is a stable, palatable product which keeps fresh for days and produces high dry matter intakes.

“We feed it to ewes in trailers every three days and it stays completely cold and fresh during that time,” he says.

Anything left is fed to the farm’s cattle when it still remains palatable and cold.

Because of its long-lasting qualities it is effectively available to ewes ad lib, which has led to a noticeable increase in dry matter intakes, less of a rush for food and a more contented flock.

Mr Ridley says: “By the end of gestation the ewes are in good condition and receive just a small amount of home-grown concentrates for the final four weeks.

“We find if they are in good condition in late pregnancy the lambs get off to a good start and never look back.”

At the earliest opportunity, lambs are moved for rearing and finishing on to high quality swards, all of which include either red or white clover.

Mr Ridley says: “We grow the best grass varieties we can and reseed every five to seven years. But there is a limit to how much red clover we can grow as we cannot tup ewes on red clover because of its negative effects on fertility.”

Red clover is often undersown with an arable silage, such as a barley, oat and pea mix. This will usually be wholecropped in August and the undersown clover used for autumn grazing the lambs.

“We will only graze it lightly in autumn, just to encourage tillering. We will return to it the following spring and possibly again the following autumn.”

With only one cut of silage taken in June, there is plenty of grazing for fattening the lambs.

Sheep breeds

Equal attention has been given to the replacement breeding programme, with the same aim of maximising performance from forage and grass. For the past four years, this has involved the use of Aberfield rams on the Texel cross Lleyn lowland flock.

Mr Ridley says: “These rams have been bred to perform on grass and would have been removed from the breeding programme if they did not do so. I buy them as shearlings and when they arrive, it is clear they have never seen a bag of feed.

“We use one ram per 30-40 ewes despite their mating capacity of 80-100, as it is important for us to lamb in a tight block.”

Selecting his rams on estimated breeding values, he says he has focused selection on maternal traits.

“We want a reasonable but not excessive lambing percentage, good maternal ability and a relatively lightweight ewe, as the larger animals require more feed for maintenance,” he says.

While building up his closed flock of breeding ewes to include the Aberfield bloodlines, also using the Aberfield SR which includes some Lleyn blood, he continues to use a Texel ram as a purely terminal sire.

Lambing percentage was 190 per cent for the March 2019 crop, which was recorded through a benchmarking service against other organic flocks with the University of Newcastle.

“This year we hope for a similar outcome for the 2020 lambing,” he says. “We do not want to scan at more than 200 per cent as this means we will have too many triplets.”

Performance

With the start of lambing less than a month away, he plans a few changes he hopes will further improve performance, including a lower stocking rate when the ewes lamb outdoors.

He says: “We normally lead the lambs in to spray navels and ring tails and once they have sucked we turn them back out. But this year we are going to try a simpler method and hope that keeping them on a larger area will reduce mismothering and incidence of infectious diseases, such as watery mouth and joint ill.

“All going to plan, this will be less labour intensive and, if the weather permits, we will not bring them in for lambing at all.”