Seasonal cyclicity in carbohydrate metabolism parameters in the European bison, Bison bonasus L.

1. In 197 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 3 years old; Group 4, mature cows, over 3 years old) seasonal changes in the level of lactic and pyruvic acids, glucose and alkaline reserve were studied. 2. Seasonal cyclicity was found only in lactic acid levels in all groups. 3. In the pyruvic acid level cyclicity was found only in males. 4. In the glucose level cyclicity was found only in mature cows. 5. In alkaline reserve cyclicity was found only in mature bison. 6. Six out of 9 acrophases of cyclic indices occurred in the period from the second half of August until mid-December, i.e. before the winter time.