POSSIBILITIES OF TREATMENT WITH GESTAGENS IN THE COW

In cattle, gestagens are used for oestrus synchronisation, for treatme nt of fertility disorders and as part of superovulation treatments. Pr ogesterone can be administered either by daily injections or via const ant release intravaginal devices (PRID). Chlormadinonacetate, which is a synthetic gestagen, can be given orally, Treatment with PRID is use d succesfully for the induction of cyclic ovarian activity in cows wit h ovarian disorders. However, after induction of oestrus in cows with abnormal ovarian function or after oestrous synchronisation, up to 30 percent of the cows did not ovulate within 2 to 3 days after the end o f gestagen treatment. This might be attributed to the fact that plasma progesterone concentrations during PRID treatment are lower than duri ng the physiological luteal phase, In combination with hormones stimul ating follicular development (PMSG, FSH), PRID can also be used as par t of superovulation treatments.