Bovine Plasma β-Mannosidase Activity and Its Potential use for β-Mannosidosis Carrier Detection

Abstract

Plasma β-mannosidase activities were determined for Salers cattle from 8 herds as an evaluation of this method for detection of β-mannosidosis heterozygotes. Several biological factors, such as age, gender, herd, and risk of being a β-mannosidosis carrier, were considered in this study. The mean enzyme activity for obligate heterozygotes (n = 8) was 55 U/ml (range = 43–65 U/ml), which was 59% of the mean enzyme activity for cattle that were low risk for being a carrier. These data indicate that bovine β-mannosidosis is characterized by a gene dosage effect. The analytical and biological variation of plasma β-mannosidase activity that was observed necessitates limiting the test to adult fullblood/purebred Salers cattle within a herd. Plasma β-mannosidase analysis provides important information for intraherd selection of Salers cattle that are heterozygous for β-mannosidosis.