“Only buy rams from accredited breeders.’’
The inherited disease is thought to have been introduced with the first shipment of Texel sheep to New Zealand over 25 years ago. If both parents are carriers (have a single copy of the mutation each), then there is a one in four chance that the offspring will be born either blind, or with no eyes.
The Texel breed has been used widely to increase meat yield.
The Registered NZ Texel Breeders organisation approached Professor Hickford to develop a robust test for microphthalmia, now the standard for the industry in New Zealand.
In 2011 the breeders group also started a microphthalmia accreditation programme. It allows for whole stud flock testing at significant discount on the test cost, so that individual breeders can be assured that they have no carriers of the disease in their flock.
Its aim is to give assurance to the commercial ram-buying industry that Registered NZ Texel Breeders who are accredited, do not have the disease in their flock.
Professor Hickford believes the scheme has made a large difference to the industry.
He feels there is under-reporting of the disease as many farmers don’t know what it is and often it is at such a low incidence that farmers don’t follow it up.
His recommendation is that if you are using Texel or Texel-cross genetics you should be asking your breeder what they have done to make sure they aren’t selling carrier animals.