& the Impact on the Beef Industry
α-mannosidosis is a lethal disorder linked to a genetic condition affecting Angus, Murray Grey and Galloway cattle. There are two versions of the condition caused by two separate genetic mutations, one affects Angus and Australian Murray Greys; the other affects the Galloway breed. These two mutations cause the same disease and both affect the same gene1. Affected calves express a number of symptoms including head tremors, uncoordination, aggression, nervousness and failure to thrive1,7. Most calves die shortly after birth or within the first year and some are aborted during pregnancy.
The recessive disease was first described in Australian Angus animals by Whittem and Walker in the late 1950s2, and before controls were put in place in New Zealand in 19744 about 3000 affected Angus animals were born annually3. The Angus mutation has also been found in North America5 and in Aberdeen Angus in Scotland6.
Since the discovery of the condition regulations have been put in place to reduce the prevalence of the mutations in New Zealand1. However continued testing is still required to ensure the prevalence of carrier animals is kept to a minimum. It may never be possible to completely remove carrier animals from the breed populations world wide.
More than 20 years after α-mannosidosis was first described, with major advances in technology, a DNA test was produced for both the Angus and the Galloway mutation1. This test is currently available through Zoetis Genetics.