APPLICATION OF CAPILLARY ELECTROPHORESIS IN THE IDENTIFICATION OF PHENOTYPES CONTAINING THE BETA-LACTOGLOBULIN-C VARIANT

A method for the separation of the beta-LG variants A, B, and C was de veloped using free zone capillary electrophoresis. A separation buffer consisting of 50 mM 2-(N-morpholino)ethane sulfonic acid (pH 8.0) and polyoxyethylene (20)-sorbitan monolaurate was used for the separation . Milk samples from 424 Jersey cows were phenotyped using this method, and the gene frequencies for beta-LG A, B, and C were .41, .53, and . 06, respectively. These frequencies were different from those found in studies of Jersey populations in other countries, where the beta-LG B allele had a significantly higher frequency, and the beta-LG A allele a significantly lower frequency, than those of this present study. Th e frequency of the beta-LG C allele was intermediate to those of other studies. The concentration of beta-LG in the milk was different among the beta-LG phenotypes and was, from greatest to least: AA, AB, AC, B E, and BC.