The milk distribution in alveolar and cisternal portions and the mammary gland morphometry were studied using 14 cows, being seven Holstein and seven Girolanda, with same parity and days in lactation, and milked twice a day. Milk yield was measured everyday, whereas alveolar and cisternal fractions were determined once a week. During the experiment, ultrasound scan measurements and morphometrical measures of the mammary gland were also performed. Girolanda cows had udder and teats larger than Holstein cows. Diameter, wall thickness, and length of the teat channel measured from ultrasound images were higher in Girolanda group, but cisternal area of the mammary gland was larger in Holstein cows. No differences in milk yield and cisternal and alveolar milk fractions between the studied breeds were observed.
dairy cow; lactation; morphometry; milking; udder
