This trial was carried out on 22 Brown Swiss heifers. All animals were injected with 500 mg of cloprostenol and then divided into three groups. Eleven days after first treatment, group 1 heifers received 500 mg of cloprostenol intramusularly. Heifers in group 2 were injected with 250 mcg of cloprostenol intramuscularly ipsilateral to active corpus luteum and group 3 heifers were treated with 125 mcg of cioprostenol intravaginally. Synchronization rates in group 1, 2 and 3 were 100, 75 and 14.3% respectively after second cloprostenol administration.
Present Adress of Authors; Selçuk University, Faculty of Veterinary Medicine. Department of Obstetrics and Diseases of Reproduction. 42020 Konya, TURKEY.