The effect of bromocryptine on plasma prolactin concentration and ovulation rate in ewe breeds with different fecundity rates

The objective of the study was to investigate the effect of bromocryptine on the neuro endocrine feedback mechanisms that control ovulation rate in two sheep breeds with different fecundity and ovulation rates (Scottish Black Face and Finnish Landrace). Bromocryptine was administered i.m. in doses of 1 mg at 12-h intervals for an entire estrous cycle (16.0 ± 0.5 days), to 12 Scottihs Black Face and 12 Finnish Landrace ewes. The aim was to record the blood prolactin levels and the effect of bromocryptine on ovulation rate. The experiment was carried out during the breeding season (November 1999) and repeated in January 2000. In the first study the ovulation rate was not affected by the low plasma prolactin (