Serum lysozyme level in the European bison, Bison bonasus (L.).

From 168 European bison divided into four groups (group 1, 0-3-year-old males; group 2, 0-3-year-old females; group 3, mature bulls, over 2 years old; group 4, mature cows, over 3 years old) the serum lysozyme level was studied. The mean lysozyme level varied from 3.91 micrograms/ml in young males (group 1) to 4.02 micrograms/ml in young females (group 2) and mature bulls (group 3); the range was from 2.10 to 6.40 micrograms/ml (only in a few animals). Statistically significant differences between months were found only in young males (group 1).