Studies on age specific leukocyte and lymphocyte counts in normal Friesian, Red Danish and Jersey cattle in Denmark

To determine reference values for leukocyte and lymphocyte counts of the most common cattle breeds in Denmark, especially regarding the evaluation procedure in the leukosis control work, blood samples from normal cattle of all ages within the Friesian, the Red Danish and the Jersey breeds were collected, transported and counted as in the routine leukosis control programme. Evaluation of breed- and age specific counts showed numerically small, but statistically significant differences in mean values of leukocytes and lymphocytes between on the one hand Jersey cattle and on the other hand Red Danish and Friesian cattle. However, it was found that the key values used in the leukosis control work are generally in good agreement with the calculated 99.87 percentiles of all age- and breed specific lymphocyte count distributions, which were approximated with logarithmic normal distribution curves.