BEHAVIOR OF SOMATIC-CELLS IN UDDER SECRETION DURING THE DRY PERIOD IN COWS WITH NORMAL OR IMPAIRED UDDER HEALTH AND CLASSIFICATION OF PHASES OF THE DRY PERIOD

The phases of the bovine dry period are classified and interpreted and illustrated by a graph. Numbers and percentages of somatic cells and their biologic behavoir were analysed quarterwise in milk and udder secretion of a total of 43 cows in two trial complexes (VK). In trial I, examinations were performed once a week over the whole dry period and in trial II, 10 examinations were carried out during the first 3 weeks of the dry period. Mean values for total cell numbers in healthy and non-healthy quarters, respectively over the total dry period were 8.2 millions/ml and 34.1 millions/ml, respectively, numbers of polymorphonuclear leucocytes (PKL) 2.6 millions/ml and 24.4 millions/ml, respectively, numbers of macrophages (MP) 3.0 millions/ml and 4.4 millions/ml, respectively, numbers of lymphocytes (LY) 1.8 millions/ml and 3.4 millions/ml, respectively, and numbers of cells that could not be differentiated (n. d. Z.) were 0.8 millions/ml and 1.9 millions/ml, respectively. Percentages were 27.8 percent and 66.1 percent, respectively for PKL, 35.7 percent and 15.9 percent, respectively for MP, 23.2 percent and 11.2 percent, respectively for LY, and 13.3 percent and 7.0 percent, respectively for n.d.Z. According to these figures, macrophages dominate in healthy dry udder quarters with relatively low total cell numbers, PKL in non-healthy dry quarters with relatively higher total cell numbers. The percentage of Lymphocytes increases throughout the dry period and in particular in its second half, whereby the percentage of ANAE-positive lymphocytes (T-LY) increases both in healthy and also in non-healthy udder quarters.