Effect of fenprostalene 14 days after fertirelin treatment on intervals from treatment to conception in cows with follicular cysts diagnosed by milk progesterone test

Of 170 cows with ovarian cysts which were detected by palpation of the ovaries per rectum, 88 cows (51.8%) were diagnosed as having follicular cysts on the basis of milk progesterone concentrations. Eighty-three of the 88 cows were used for treatment trials. A group of 56 cows injected subcutaneously with fenprostalene, prostaglandin F2 alpha analog, 14 days after treatment with fertirelin, an analog of gonadotropin-releasing hormone, compared with another 27 cows treated only with fertirelin (controls), showed a higher pregnancy rate within 100 days after the initial treatment (66.1 vs 48.1%) and shorter intervals from the treatment to conception (30 +/- 21 vs 43 +/- 27 days). It was concluded that the administration of fenprostalene following fertirelin treatment is effective in shortening the interval from treatment to conception in cows with follicular cysts.