Lysosomal alpha-mannosidase is a broad specificity exoglycosidase involved in the ordered degradation of glycoproteins. Deficiencies in this enzyme result in global metabolic disorders in cattle.
There are two variants of this disease:
- α-mannosidosis - Aberdeen Angus, Murray Grey, Brangus, Simmental, Galloway, and Holstein cattle.
- β-Mannosidosis - primarily Saler cattle.
Cattle affected with α-mannosidosis show signs of abortion, neonatal deaths, and in young calves, ataxia, head tremor, aggression and failure to thrive. Most affected calves die within the first year.
In Salers cattle affected by β-Mannosidosis, calves show signs of recumbency and ataxia.
Diagnosis of these diseases requires PCR assay sampling of suspect cattle.
There is no specific treatment for affected cattle, and crossbreeding in commercial beef production has helped reduce the significance of this recessive defects.
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