25 August 1995


Selecting quality lambs has never been more important, yet some commercial sheep producers are still falling far short in their selection of finished lambs. Worcs farmer and lamb buyer Robert Smith has some innovative ideas for improving the selection process, as he told Jeremy Hunt

ROBERT Smith views the prime lamb market from every angle – as a Worcestershire farmer running 250 breeding ewes, as a lamb buyer handling over 1000 lambs a week for a major wholesaler and as a well known victor of many carcass competitions at top level. But in his opinion commercial sheep producers are still falling far short in their selection of finished lambs.

The "feel" of the loin and the "grip" of the dock are by far the most widely used tests to assess levels of "cover" The industry has been warned off using the word fat but in fact that is exactly what producers are feeling for because too much of it is what will, increasingly, lead to hefty discounts on prime lambs.

Mr Smith has some refreshingly new and innovative ideas for ensuring the right lambs are sold at the right time. Not necessarily to earn big premiums but to help avoid attracting the lower prices about to hit those who fail to meet the R,U and E 2 and 3L specifications of the export-led market. This market, he believes, is gearing itself up to exert a level of pressure on prices never before experienced by the UK sheep sector.

Mr Smith sees the lamb market becoming intensely "picky" in its demands for the very best carcasses. For the past decade, producers have been coerced into improving their selection of finished lambs but price differentials, though in operation, have never posed the threat the industry now faces.

"There is still a big gap in the way farmers regard the different selection points in relation to the actual carcass and the depth of eye muscle," says Mr Smith.

His own flock at Grove Farm, Bishampton, near Evesham, now looks to the Beltex as the main terminal sire. It is a breed thats been responsible for Mr Smiths recent successes in carcass competitions but is also one that provides the perfect opportunity to demonstrate that "all you see is not all you should feel".

Two pedigree Beltex rams, both with extreme hindquarter muscling, were used by Mr Smith to demonstrate the only way to evaluate fully the depth of gigot when selecting prime lambs. One of the Beltex rams appeared visually to have more hindquarter development; eye appraisal was confirmed when the gigots were handled in the traditional manner from behind the sheep.

But what a different story when the flat of the hand was placed up and inside the thigh of these rams. The depth and thickness of the muscle tissue on the ram with the slightly smaller gigot seen from behind, was quite exceptional. The other ram less so, even though when felt in the usual way the gigot appeared wide.

"I know we are using pedigree Beltex rams here but the procedure is the same for prime lambs. An estimation of the depth of gigot cannot be gained either by looking or feeling the sheep from behind. You must feel under the hind leg and up into the hindquarter. It never fails to surprise people just what a different picture that gives.

"If you can imagine a carcass hanging up, its the muscle on the inside of the leg thats important; its the depth of the loin that actually determines the size of the eye muscle."

The absence of wool on the inside of the back leg, which is only covered by hair, gives a true picture of the fullness of the muscle. It can be measured by turning both hands into calipers and by spreading the outstretched hands to span the front and back of the hind leg with the aim of both thumbs touching on the outside to give an idea and "feel" of muscle depth.

"I dont see any reason why a real caliper measurement of terminal sires could not be taken and the width incorporated into existing recording data for ram evaluation," says Mr Smith.

He dismisses any suggestion that the inside leg method is impractical for commercial lambs. "I select 1000 and more lambs a week and provided they are in a race it poses no problem. I place my hand over the loin to assess depth and finish of the loin and then slip my hand up and under the inside of the hind leg."

Mr Smith has been buying lambs to meet a tight French export specification and says his methods are ensuring that he doesnt have to buy 800 lambs to find 400 to meet the order, which other less effective methods of selection would require.

And still in the same area of the lamb is the "catch" or the skin just under the hind leg. Again this is an area devoid of wool; pinch it and if it feels "squidgy" you know you have an over-fat lamb; if you pinch skin-to-skin the lamb is lean.

The tail-dock has long been a convenient though not always totally reliable "check" for finish. Some Continental crosses have a tendency to be fat through the shoulder and the top of the loin while still feeling "thin" in the dock. Mr Smiths approach is to feel for a "crack" just beneath the skin above the tail-head. This will be felt as a ridge for lambs falling into fat class 1 and 2; 3L lambs have a flatter feel while the ridge begins to open up and widen for 3H and 4L lambs.

How to use the skin just above the hindleg as a "feel factor" in assessing cover. If its "squidgey" you know its likely to be carrying too much finish.

Above:How to feel for the crack just beneath the skin above the tail-head. If a "ridge" is felt it means the lamb is in Fat Class 1 or 2; 3L lambs have a "flatter" feel while the ridge begins to "open up" and widen for 3H and 4L lambs. Below: Two Beltex rams. Although the one on the left appears to have the better hindquarter, by feeling for "depth" of hindquarter it becomes clear that the ram on the right is superior.

New ideas for helping to select quality carcasses. It is more important to feel into the hindquarter from the side and through to the thigh to ascertain depth of flesh, rather than feel from the back, points out Robert Smith.