17 November 1995


SIRE reference schemes have been on the scene for five years now. The Suffolk and Charollais schemes were working with 39 flocks in 1990. Now nine breeds have a total 140 flocks participating in breed improvement.

Their common objective is to breed top quality sires which will produce superior lambs to meet todays and future markets.

It is a long term project though, points out Stewart Hall, the Meat and Livestock Commissions (MLC) sheep strategy manager. But already some flocks are selling 80% of their rams straight off the farm on breeding value figures alone. For example, Charollais rams have been sold, priced on index with a base of £300, plus £2 an index point over 100 points.

The schemes are limited companies. MLCs role is developmental, working side-by-side with the secretaries and Signet consultants.

"MLC has a responsibility over sheep breed improvement. We develop the schemes and progress them forward," explains Mr Hall. "We provide the latest technology and help the breeder use it to the industrys benefit.

"Breeders are provided with estimated breeding values (EBVs) on membership of a sire reference scheme and Signets Sheepbreeder service. An EBV provides comparison of animals which are superior or inferior compared to other animals in a group. They are expressed as a measurement of the trait recorded, eg eye muscle and backfat are in mm and weight in kgs."

Best linear unbiased prediction (BLUP) analysis is then used to compare ram performance across flocks and produce a scheme index. Values over about 130, depending on breed, indicate rams which are faster growing and leaner than the scheme average. This system removes variations in management systems between flocks. BLUP analysis is only currently available to sire reference schemes, but is forecast to be available to all Sheepbreeder members sometime next year (see table).

There are three terminal sire schemes exhibiting at Farmtech: Suffolk, Texel and Charollais. The Blue-Faced Leicester, a long wool crossing breed, will be represented by its group breeding scheme. Since their conception all have shown impressive progress.

All rams are progeny-tested before they are used. The Charollais and Suffolk sire reference schemes select, then progeny test. The Texels progeny test and then select.

Each breed has an individual approach to forging genetic links between flocks, with most preferring AI due to geographical constraints. Most of this technology involves frozen semen, except for Texel members who are able to use fresh semen as the rams travel from farm to farm.

AI is one of the biggest potential barriers preventing sire reference scheme membership snowballing. The technique does not fit into many farm systems and is not cheap. Such a breeding programme can cost a producer thousands of pounds.

This argument, of course, does not take into account the financial benefits waiting for producers who invest in rams with high indexes. Scottish Agricultural Research shows returns can improve by an extra £2 for lambs sired by a high index tup.

To overcome the AI problem, MLC invested resources into researching non-invasive methods of AI using frozen semen. "The results had not been as successful as we had hoped and MLC is now funding alternative approaches to this problem," says Mr Hall. Instead, the project has been taken up the Scottish Office which has commissioned Edinburgh Genetics and a Scottish institute to continue the work.

Selection base

Conscious of the need to encourage more producers to join reference schemes, and hence increase the genetic selection base, MLC has commissioned work with the Scottish Agricultural College to see how many ewes really need to be mated within each flock to provide enough data to compare rams. Currently, each scheme stipulates members must put a set number of ewes, usually about 30, to sire reference rams. This is a large commitment for many pedigree flocks.

Instead the two-year long research, under Ron Lewis guidance, will look at genetic linkage, with the aim of producing an individual menu for each flock as to what AI use is required to guarantee comprehensive cross-flock comparisons.

"If a new flock comes into a scheme, it may already have been buying sire reference rams and therefore will not need to put so many ewes to sire reference rams," explains Mr Hall. "The beauty of sire reference schemes is that all members, old and new, have the potential to produce high index stock and contribute to breed improvement."

Gene mapping profiles is another area to be explored. "The technology is available and the potential there to make good use of it," says Mr Hall. &#42

Sheepbreeder scheme

Basic annual feePrice (£)Signet Staff visitsService provided

No Timing

Up to 50 ewes2602on requestWeighings and/or results

51-150 (£/ewe)1.45often wheninterpretation and

8-week andbreeding advice. Full

+150 ewes (£/ewe)0.50scanningbureau data service

Maximum430resultsusing computer-generated

availablepre-lists giving 8-week

indexes and range

of breeding reports.


cost a lamb(£)1.551Usually whenWithin flock index

lambs 140/produced. Across flock

147 days or BLUP analysis for sire

as shearlingsreference scheme and

breeding group members

Within flock BLUP analysis

under development for

Minimum day visit fee(£)83non-group flocks.

Charollais shearling ewe from Dai and Cynthia Morriss Penywern flock made the top price of 1850gns at a recent sale. She has an index of 155.