Amylase genetic variation of serum in Holstein cattle.

Three amylase phenotypes, AmIB, AmIC, and AmIBC, were detected by electrophoresis of blood serum from 329 Holstein cattle. These phenotypes appear to be controlled by two alleles AmIB and AmIC at the amylase I locus (AmI). Frequencies were .518 and .482 for alleles B and C. The numbers of phenotypes corresponded closely to expectations of Hardy-Weinberg equilibrium. No evidence of linkage between the AmI locus and other genetic marker loci of blood and milk was detected.