New Zealand farmers no longer think in terms of breed, with many now marketing stock on the basis of specific genes, such as the Inverdale high fecundity gene.

These genes have been bred into many mainstream breeds, with breeders now selling Romneys with the Inverdale gene, said New Zealand farmer Murray Rohloff.

“Unregistered flocks have also come to the fore, with 80% of Romney rams sold in New Zealand unregistered.

“But while science has not been the main catalyst for change, it has come to the aid of breeders.”

Mr Rohloff said gene markers were the next generation of scientific developments coming forward.

“These will allow the introduction of singe-effect genes through introgression, thereby keeping the desired trait, but eliminating the rest of the other breed characteristics.

“This should also speed up the introduction of novel genes within a breed for traits such as muscling and disease resistance,” he added.