The effect of repeated administration of Oestrophan on the quality of sexual function in breeding stock

The objective of the study was to check a contingent negative effect of repeated treatment of heifers by PGF2 alpha--Oestrophan --on the course and quality of their ovarian activity and external heat signs.
Changes in progesterone concentrations were evaluated three times a week. Three heifers were subjected to treatment eight times and two heifers nine times. Of 42 applications of Oestrophan the response was positive in 95.2% (forty heats). When Oestrophan ) was administered on the fourth and sixth day of the sexual cycle, in two cases no heat nor luteolysis of corpus luteum was detected; this was demonstrated by hormonal investigation.
Of the forty evaluated heats, 82.5% were classified as strongly and medium expressive, the remaining were weakly expressive. The onset of heat was found to be on the average 72.6 hours after Oestrophan administration, in 9.1% of the cases the heat started about 48 hours after administration, 12.4% of cows showed the heat signs between 72nd and 96th hours.