The Relationship Between β-Lactoglobulin Phenotypes and Milk Composition in New Zealand Dairy Cattle

Abstract

Bulk milk collected from β-lactoglobulin AA phenotype cows had a composition that was markedly different from that of β-lactoglobulin BB phenotype cows. The β-lactoglobulin AA phenotype bulk milk had 28% higher whey protein concentrations, 7% lower casein protein concentrations, 11% lower fat concentrations, and 6% lower total solids concentrations than β-lactoglobulin BB phenotype bulk milk. The higher whey protein concentrations in β-lactoglobulin AA phenotype bulk milk result from large increases in β-lactoglobulin concentrations in this type of milk. However, concentrations of α-lactalbumin were lower in β-lactoglobulin AA phenotype bulk milk. Apparently high concentrations of β-lactoglobulin or the presence of the β-lactoglobulin A variant gene suppresses the synthesis of the other major milk proteins. © 1993, American Dairy Science Association. All rights reserved.