22 March 1996

Computer mating picks best

DAIRY producers keen to secure the best possible matings for cows in their herd are being offered the help of a computer mating program.

Launched last week by the Holstein-Friesian Society, Select-a-Bull is available to both pedigree and non-pedigree producers. The HFS anticipates it will improve genetic progress by overcoming prejudices based on the reputation of a bull or company.

Producers must have their herd assessed for type to use the service. This gives the HFS data for its national type file. This will benefit the industry by improving the accuracy of type proofs, it claims.

Select-a-Bull is based on the principle of corrective mating. "Its strength is that it allows producers to select minimum type and production criteria for sires to meet," says HFS head of breed development David Hewitt. These include PTA (and its components), PIN, ITEM, Type Merit, and the four composite traits of body, dairy, legs and feet, mammary.

Sire database

The computer stores a database of all UK and foreign sires that have type and production indexes converted to Interbull standards. It selects those which meet the chosen breeding goals and draws up a short-list.

Each cow in the herd is also evaluated for linear type traits.

The computer then pinpoints the most suitable bulls from the short-list for each individual cow. Selection is based on the type characteristics of the sires and cow. It suggests three matings a cow. These are as close as possible to an HFS devised ideal type. The computer gives a % suitability to each corrective mate to illustrate how close the progeny are expected to come to that ideal. It also predicts the PIN and type of the progeny.

Mr Hewitt stresses that although this final selection is made on type not production, the production index of sires can be set as high as required. Producers can also change the type ideal if their breeding goals differ to the national standard. Cost is £1 a mating plus £3 for the linear assessment or £5 for classification. Non-pedigree producers could use the service for £4 a mating. &#42