Physiological and pathological factors influencing bovine alpha-lactalbumin and beta-lactoglobulin concentrations in milk.
Bovine alpha-lactalbumin and beta-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. alpha-Lactalbumin and beta-lactoglobulin concentrations were not affected by quarter location. The alpha-lactalbumin decreased at the end of lactation and in samples collected beyond second lactation. The beta-lactoglobulin concentration increased with stage of lactation. There was a positive correlation between alpha-lactalbumin and beta lactoglobulin (r = .12). Milk from uninfected quarters had mean alpha-lactalbumin and beta-lactoglobulin concentrations of 1.47 and 4.6 mg/ml, respectively. Milk from quarters infected by major pathogens or Corynebacterium bovis had less alpha-lactalbumin. Milk from quarters infected by minor pathogens had less beta-lactoglobulin. There was a negative correlation between alpha-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 beta-lactoglobulin concentration when considered over the whole sampling period, but the correlation became negative in quarters infected by major pathogens.
D000818:Animals; D002417:Cattle; D003354:Corynebacterium Infections / Q000503:physiopathology / Q000662:veterinary*; D005260:Female; D007768:Lactalbumin / Q000032:analysis*; D007774:Lactation / Q000502:physiology*; D007782:Lactoglobulins / Q000032:analysis*; D008414:Mastitis, Bovine / Q000382:microbiology / Q000503:physiopathology*; D008892:Milk / Q000032:analysis*; D011247:Pregnancy; D013203:Staphylococcal Infections / Q000503:physiopathology / Q000662:veterinary*
D007782:Lactoglobulins; D007768:Lactalbumin