Effects of intravulvo-submucosal cloprostenol injections on hormonal profiles and fertility in subestrous cattle

Eighty-two subestrous cattle were treated with different doses of cloprostenol through intramuscular (i.m.) and intravulvo-submucosal (i.v.s.m.) injections to study hormonal profile and fertility. The study was divided into two experiments. In Experiment I, 13 cows were treated with one of three doses of cloprostenol (500 mug i.m., 125 and 62.5 mug i.v.s.m.) to measure response of progesterone (P(4)) and estradiol (E(2)). P(4) decreased abruptly and E(2) levels increased from basal levels following injections of the two larger doses of cloprostenol. P(4) decreased to<5 nmol/l approximately 72 h after treatment. E(2) levels increased to >300 pmol/l 24 h after cloprostenol injections except in cows treated with 62.5 mug dose. Close agreement was observed between P(4) profiles and clinical findings following 500 and 125 mug of cloprostenol treatment. In Experiment II, 69 subestrous cows were treated with either 500 mug i.m. or 250, 125 or 62.5 mug i.v.s.m. doses of cloprostenol. The percent of cows in estrus 96 h following treatment were 60, 80, 67.8 and 18%, respectively. A total of 29 cows were artificially inseminated and 41.3% conceived. We concluded that i.v.s.m. injections of cloprostenol at the dosage of 125 mug and above causes luteolysis, induces estrus and establishes fertility in subestrous cattle. The method is economical but time consuming when compared to the intramuscular route.