J. Schulz et al., DECREASE OF THE LACTOSE CONCENTRATION IN COWS MILK AS A RESULT OF INCREASED PERMEABILITY OF THE TISSUE BARRIERS BETWEEN MILK DUCTS AND BLOOD, Praktische Tierarzt, 79(7), 1998, pp. 657
Published data on lactose concentrations in milk and urine of cows ind
icate, that both the decrease of this genuine product of the mammary s
ecretory cells in the milk and its appearance in urine are connected w
ith mastitis, severe general diseases (fever, anorexia), prolonged mil
king intervals, application of high doses of oxytocin, drying off and
onset of lactation at parturition. The lactose transfer from the milk
into blood and urine occurs predominantly during the storage of the mi
lk within the alveolar lumina, milk ducts and cisterns. Own results sh
ow, that the extent of the changes of the lactose concentration in mil
k and urine reflects the severity of mastitis, the degree of medicamen
tal udder iritation, the method of drying off and physiological struct
ural changes of the mammary tissue. Lactose values in urine of below 0
,5 g/l characterize good udder health and regular udder evacuation. At
parturition, around day 3 after drying off and at the beginning of an
acute mastitis peak values of more than 4g lactose per liter urine ca
n be expected. The urinary lactose content reflects the state of integ
rity of the tissue barriers (tight junctions of mamary epithelia) betw
een milk and blood.