Physiological and Pathological Factors Influencing Bovine α-Lactalbumin and β-Lactoglobulin Concentrations in Milk

Abstract

Bovine α-lactalbumin and β-lactoglobulin concentrations were determined by radial immunodiffusion in 354 milk samples from uninfected and 98 samples from infected quarters from 42 Holstein-Friesian cows taken at 30, 150, and 270 days of lactation. α-Lactalbumin and β-lactoglobulin concentrations were not affected by quarter location. The α-lactalbumin decreased at the end of lactation and in samples collected beyond second lactation. The β-lactoglobulin concentration increased with stage of lactation. There was a positive correlation between α-lactalbumin and β lactoglobulin (r = .12). Milk from uninfected quarters had mean α-lactalbumin and β-lactoglobulin concentrations of 1.47 and 4.6 mg/ml, respectively. Milk from quarters infected by major pathogens or Corynebacterium bovis had less α-lactalbumin. Milk from quarters infected by minor pathogens had less β-lactoglobulin. There was a negative correlation between α-lactalbumin concentration and somatic cell count (r = .31), which was amplified by infection status of quarters. No correlation was noted between somatic cell count and β-lactoglobulin concentration when considered over the whole sampling period, but the correlation became negative in quarters infected by major pathogens. © 1985, American Dairy Science Association. All rights reserved.