13 October 1995

South-west unit swears by year-round lambing

Year-round lambing helps secure an even cash-flow and improved fertility on one Devon unit.

Rebecca Austin reports

EWES lamb 48 weeks of the year at Sir Jack Boles Rydon Farm, Talaton, Devon.

Cash-flow is more even, the sheep and workforce is used to full potential, and the buildings dont stand empty for most of the year.

But simplicity is the underlying theme, insists farm manager Andrew Dinnis. And with up to a quarter of the 1100 ewes lambing twice a year, he has also noticed improved fertility within the flock.

He and his wife Jennifer lamb the ewes in three groups. The system stems from the autumn-lambing flock when nearly 800 ewes lamb between October and December. To achieve this rams are put in during June and July.

Early the following year, just before the autumn-born lambs are weaned, the rams go in again with ewes mothering singles or potential cull ewes. These ewes, which total about 200 head, will then lamb during June or July. Again some bearing a single lamb, or those which did not take to the ram earlier and selected older ewes will be mated in the early autumn to lamb February and March. And so the cycle continues.

The system is kept simple by making sure one lambing doesnt flow into another. "The secret to tight lambing is taking the rams out," says Mr Dinnis. "We tried sponging ewes to tighten the lambing period, but it was a waste of money. Now if a ewe isnt mated she will go in with the next take."

Mr and Mrs Dinnis have noticed that when ewes bear a single in the spring they often produce doubles or trebles that autumn. "Dorsets just need to look at grass to put on fat so our system suits them and the farm well. But we dont have to starve them. We operate a high stocking rate of 17/ha (7/acre) and they just milk off their backs. When it comes to tupping they are in the right condition," says Mr Dinnis.

"Even though the breed is renowned for its ability to lamb out of season, we always provide phosphorus-based blocks for fertility and introduce teaser rams 17 days before the proper rams go in. They generally cover 30 ewes each, so they are not overworked."

Whatever the season ewes mother their lambs indoors for a few days post lambing. The spring and winter lambers are also housed at night prior to lambing. Summer lambers are fed 0.5kg (1lb) of 17% protein mix of oats, barley, sugar beet and concentrates 14 days before they are due. Spring lambers are introduced to this six weeks before lambing and the autumn group three to four weeks before – as well as six weeks afterwards for those with doubles. All three groups receive a 7:1 pasteurella vaccine and are wormed before lambing.

The Dinnises have started to introduce another breed into the flock which also claims year-round lambing ability. The Berrichon du Chers superior carcass qualities, as compared to the Dorset, are another point in its favour.

Lambs are already grading well with 90% selling direct to Devon abattoir Lloyd Maunder at 17kg to 18kg deadweight, U3L. Any surplus ewe lambs are in demand from neighbours as replacements.

The abattoir is prepared to offer a premium as Rydon Farm guarantees a certain number of lambs the year round and is FABBL-approved. autumn-born lambs are weaned on to creep and reared indoors so the Dinnises are able to meet the Easter trade at the right time. Otherwise lambs are finished at grass and, at 1.8 lambs sold a ewe, all are gone four months from lambing.

"Selling lambs throughout the season means we catch the highs and lows, but we also spread our risks," says Mr Dinnis. "We have been using this system for about five or six years now. It does wonders for our gross margin (see table) because the same number of ewes are producing more lambs in their lifetime without the need for extra buildings or labour."


Research round-up

Effect of nutrition during foetal and early life on adult health

&#8226 Underfeeding ewes in early pregnancy results in any female offspring producing a higher proportion of singles, rather than multiple births, in their first three lamb crops.

Embryo survival and growth

&#8226 Maintaining ewes on a high plane of nutrition post tupping is likely to increase embryo loss as a higher rate of metabolism removes progesterone – essential for embryo development – from the blood stream more quickly.

&#8226 Once an embryo has implanted on the uterine wall, one of the proteins it secretes is Pregnancy specific protein B which provides a more accurate pregnancy diagnosis than progesterone, as well as a good indication of foetal well being.

&#8226 Introducing rams five to six weeks after implantation increases the number of ewes holding to first service.

Foetal and young lamb development

&#8226 Ewes experiencing sub-clinical cobalt deficiency in the first half of pregnancy are likely to produce lambs with inferior lamb vigour at birth, as well as depressed passive immunity. The situation cannot be prevented by correcting the deficiency later in pregnancy.

&#8226 Selenium, as well as iodine, is now recognised as holding an important role for enhancing lamb vigour.

&#8226 Maternal exercise stimulates foetal glucose uptake and efficiency.

&#8226 Source; Dr John Robinson, SAC.


Rydon Farm gross

margin 1994

£

Lamb sales 87,845

Wool 2,840

Ewe premium 20,530

Total 111,215

Less:

replacements 14,926

lambs not yet sold 5,146

OUTPUT 91,143

Variable Costs:

Feed 21,030

Forage 7,020

Vet & Med 3,596

Misc 3,827

Total 35,473

Gross margin 55.52

Source: Signet