Antler growth in male and female reindeer and its relationship to sesonal blood levels of alkaline phosphatase

The rate of antler growth in male reindeer is one of the most intense in al l cervid species. During the fastest period of growth, the formation of new antler bone at the tip of the main beam can reach up to 2 cm per day. The aim of this study, was to elucidate the relationship of alkaline phosphatas e (AP) (an enzyme involved in bone building) and the intensity of antler gr owth in male and non-pregnant and pregnant female reindeer. The intensity o f antler growth was determined by measuring the length of the main beam and the three longest tines (brow, bet and trez) every three weeks from the fi rst sign of antlerogenesis (in males starting in February, in females in Ap ril) until the mid June. In both cows and bulls, the speed of antler growth correlated well (P < 0.001) with blood levels of AP, which in bulls reache d peak values of more than 170 International Units/liter. Peak AP levels in cows were lower than in bulls. Non-pregnant cows exhibited higher AP conce ntrations than the pregnant ones.