title: [Variability in the levels of carotenoids and vitamin A in the blood serum and milk of cows].
abstract: Observations of 20 milk cows of the lowland black and white breed were conducted for 14 successive days in four seasons of the year. The age, lactation stages and efficiency of the animals were different. They were divided into two groups: the first with healthy udders (clinically, bacteriologically, cytologically); the second with secretion disturbances and mastitis subclinical. Blood and milk samples were taken every day during the morning milking. The content of carotenoids and vitamin A was determined by the methods of Carr-Price. Although the same feeding and environment conditions of the animals were maintained, the determined levels of the studied components of both body fluids showed a great variation. Significant differences were found between the mean values calculated for individual cows (individual variability). In the milk of cows from group II, a higher concentration of carotenoids and vitamin A was found. It is proposed to assume a physiological minimum of 30 mcg/100 cm3 for vitamin A and of 100 mcg/100 cm3 respectively for carotenoids in blood serum and 100 mcg/100 cm3 and 5 mcg/100 cm3 respectively in milk.
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000097:blood / Q000378:metabolism*; D002417:Cattle / Q000097:blood / Q000378:metabolism*; D002940:Circadian Rhythm; D005260:Female; D008414:Mastitis, Bovine / Q000097:blood / Q000378:metabolism; D008892:Milk / Q000378:metabolism*; D012621:Seasons; D014801:Vitamin A / Q000097:blood / Q000378:metabolism
chemical_list: D014801:Vitamin A; D002338:Carotenoids
vernacular_title: Zmienność w zawartości karotenoidów i witaminy A w surowicy krwi i mleku krów.