15 September 1995

FASTER BULL PROOFS

HERD SYSTEM SHOWS MERIT

THE best way to identify the true genetic merit of top cows is in a single nucleus herd when all are managed in the same way.

That is the thinking behind Genuss decision to increase use of its Northumberland-based MOET nucleus herd to evaluate top cow families for contracting young bulls for its Sire Improvement Programme (GSIP).

It hopes to produce 50 bulls a year from the top 15 cows in its MOET herd. These will be flushed with top bulls world-wide. A further 20 will be selected from embryos produced from maiden heifers proven in the nucleus herd.

Embryos will also be bought from cows in the UK and abroad. These will be implanted in recipients to produce 80 bulls, with 25 bulls bought mainly from UK herds.

The top 100 of the 175 will be chosen for testing through GSIP. Its success will depend on the ability to assess the best families by sibling testing, claims Bob Strathie, operations manager for the MOET herd at Bays Leap.

He cites studies by Genuss Dr Brian McGuirk to show that evaluating top cow families for contracting young bulls is successful.

This is because there is no preferential treatment of cows in the nucleus herd, so equal emphasis on dam and sire proofs is justified.

Dr McGuirk has shown that the actual predicted transmitting ability for dams in most herds is 15% not 45%, which is used for the basis of parent average proofs. But the sire proofs are more reliable, as they result from many daughters in different herds.

In addition sibling predictions made for MOET Masters bulls have proven to be more accurate than pedigree predictions and very close to average progeny test results for these bulls.

MOET Masters whose families were tested through the nucleus herd produced progeny test proofs less than £1 different from their sibling test proofs.

The 12 MOET bulls tested had average pedigree indexes of £51, sib-test proofs of £55 and progeny test proofs of £55. For non-MOET families 22 bulls had average pedigree indexes of £54, sib-test proofs of £49 and progeny test predictions of £41.

"MOET herd females must be as good as we can get outside the herd, coupled with better accuracy the progress will be faster," says Mr Strathie.

&#8226 Sources international genetics from the USA, Holland, France, Germany and the UK.

&#8226 Manages the GSIP progeny testing scheme.

&#8226 Tests females through the MOET nucleus herd.

TO further increase genetic progress and increase efficiency, Genus has set up a co-ordinated Dairy Breeding Programme.

It will source bulls, progeny test males through GSIP, and test females in the MOET herd.

Mr Strathie says improvements in monitoring GSIP testing will improve control over semen use and so speed its use.

This tighter control, and Animal Data Centre use of "records in progress" to predict heifer lactations, will produce bull proofs six months earlier, when the bull is under five years old.

"Over the last few years better genetics entered progeny testing but the organisation wasnt very good," he says.

UK bull testing was too slow to supply proven bulls for sale because by the time the proof was produced their ranking was too low compared with that of foreign bulls, he reasons. As a result breeders have been dependent on imported genetics. "If these UK bulls had proofs 18 months earlier they would have been more competitive in the market place," he says. &#42


GENUS PROGRAMME

"Improvements in monitoring GSIP testing will give better control over semen use and so speed its use" – Bob Strathie.