Gene technology boosts fertility in ewe lambs

Prolific crossbred ewes and more valuable wether lambs are on the cards for Welsh farmers taking part in a revolutionary breeding project.


The main product of the initiative will be a robust, prolific crossbred ewe with good conformation, which will carry the Inverdale gene discovered in Romney sheep at the Invermay Research Centre in New Zealand.


Innovis, the Aberystwyth-based company behind the initiative, will supply mainly Texel rams carrying the Inverdale gene – attached to the X chromosome – to contracted farmers running hill breeds.


Trials have shown it increases the fertility of ewes sired by tups carrying it.


Aberdaron-based farmer Gareth Roberts has used two Inverdale gene carrying rams on 150 of his 250 Welsh Mountain ewes, in place of the more traditional Bluefaced Leicester.


“If the crossbred ewe lambs produced are 0.6% more fertile as predicted, then those out of Welsh ewes should be capable of 190% plus lambing,” says Mr Roberts.


Lambs should also have far better conformation than those out of traditional Mules and command a higher market price for finishers.


So Mr Roberts is hoping that male crossbreds will have better backends than Mule wethers and make more money.


His own experience of the 100 Mule ewes he runs suggests they do not last well.


They also lack shape, which can be carried through to their lambs even when a heavily muscled tup is used.


“I know Mule ewes are popular, but too many Bluefaced Leicester breeders supplying rams concentrate on breed points like ears, so conformation suffers.


“I like the way Innovis is applying science to come up with an alternative.


Many Mule producers will probably be attracted by the idea of receiving a previously agreed price for females and having better conformation male lambs to finish.”


Bardsey Island producers David and Libby Barndon, who are producing Innovis ewe lambs from 500 Welsh Mountain ewes, also hope to see these benefits.


Since they moved to the 178ha (440 acre) island in 2001 they have bred a young flock of ewes and require few replacements.


But they have also found that having to move stock by boat reduces marketing flexibility.


“Everything has to go before the onset of winter, regardless of trading conditions, so the idea of selling all ewe lambs at one time for a fixed price is attractive,” says Mr Barndon.


“Male lambs should also have a better shape and plenty of hybrid vigour, so there appear to be plenty of benefits from getting involved in this project.”


Farmers using Inverdale rams in the project will be paid an annual management fee for producing ewe lambs achieving an agreed weight in August or September.


These will be owned by Innovis and sold to prime lamb producers under the brand Line 20, says Innovis managing director Dewi Jones.


Multiplier flocks retain the money realised by selling male lambs, which will not carry a copy of the gene.


“The annual payment is fixed in advance and is a little higher than a lamb of the same weight might make sold for slaughter in September,” says Mr Jones.


“In effect we are buying ewe lambs from multiplier farms, but the system puts the onus on breeders to produce females weighing half their mature body weight and to follow the terms of their contracts.”


Mature crossbred ewes should weigh 60-65kg and only require a maintenance ration at tupping to achieve a target 200% lambing.


Buyers will receive a management blueprint, including advice on rationing to ensure ewes do not produce unmanageable litters of lambs.


“All accepted female lambs are cleared off the farm in one movement, leaving ground clear for flushing ewes and finishing male lambs.”


Line 20 ewe lambs will go directly to customers without contact with other sheep.


Participating breeders will also have to be open about the health status of their flocks and report any disease breakdown, adds Mr Jones.


“We are trying to develop an integrated and technical approach that makes best use of the sheep industry’s existing structures and the genetics in place in the UK,” he adds.


bobdavies@agrinews.fsnet.co.uk