The effects of ketoprofen on ovarian function in dairy cows

Abstract

Two experiments were conducted to investigate the effects of ketoprofen on ovarian function in dairy cows. In experiment I, eight non-milking dairy cows were administered a 0.9% saline solution daily from day 8 (day −3) of ensuing synchronized estrous cycle at 24-h intervals over 4 days (control observation). After an estrous cycle rest, the cows were given the recommended daily therapeutic dose (3 mg/kg, i.m.) of ketoprofen (Ketofen 100; 10%, Merieux/Webster, Australia) from day 8 (day −3) of the synchronized estrous cycle at 24-h intervals over 4 days. All cows received an intramuscular injection of prostaglandin ${\text{F}}_{{{\text{2}}\alpha }}$ (30 mg, Lutalyse) either 6 h before the first treatment of saline solution or 6 h before the first injection of ketoprofen. Ultrasonography of the ovaries was performed daily from the day before (day −4) experimental treatments until day 2 after induced estrus, to monitor the growth of the ovulatory follicle and ovulation, and then on day 9 after estrus to determine the presence and the size of the corpus luteum. In experiment II, five non-milking dairy cows were used in two successive observations. The plasma preovulatory estradiol-17β peak and progesterone concentrations were determined, and ovarian ultrasonography was performed to determine ovulation and corpus luteum development. Results obtained from experiment I showed that the diameter of dominant ovulatory follicle on day of estrus was significantly (p<0.05) higher in saline-treated estrous cycle compared to that of ketoprofen-treated cycles (13.8±1.3 vs 10.9±0.4 mm). Furthermore, by 48 h after standing estrus, ovulation had taken place in seven of eight saline-treated estrous cycles, whereas only three ketoprofen-treated cows had ovulated by 48 h after standing estrus (p<0.05). A significantly (p<0.05) higher mean estradiol-17β peak was observed in ketoprofen-treated estrous cycles at estrus compared to that of the control estrous cycles (experiment II). Additionally, a significant (p<0.05) daily increase in the mean plasma progesterone concentration was observed after ketoprofen treatment beginning from day 0 to 6 of the subsequent estrous cycle (p<0.05). The results of the present study demonstrate that administration of ketoprofen during the pre- and periovulatory period of the estrous cycle in dairy cows impairs final growth of ovulatory follicle, leading to a disturbance in the normal process of ovulation.