POTENTIAL OF DESLORELIN AS INDUCTOR OF OVULATION FOR TIMEDARTIFICIAL INSEMINATION IN PRIMIPAROUS Bos taurus indicus COWS/POTENCIAL DA DESLORELINA COMO AGENTE INDUTOR DA OVULACAO EM VACAS PRIMIPARAS Bos taurus indicus NA INSEMINACAO ARTIFICIAL EM TEMPO FIXO/POTENCIAL DE LA DESLORELINA COMO AGENTE INDUCTOR DE LA OVULACION EN VACAS PRIMIPARAS Bos taurus indicus EN LA INSEMINACION ARTIFICIAL EN TIEMPO FIJO

The aim of the study was to verify the efficiency of deslorelin (DES) as inductor of ovulation in timed-artificial insemination (TAI) protocols on pregnancy rate (PR) in primiparous Bos taurus indicus cows. Hundred seventy six animals were divided into three groups (G): GNDES (Group No Deslorelin; n = 59) which received on day 0 (d0) an intravaginal device with 0.558 g of progesterone (P4) + 2.0 mg estradiol benzoate (EB) (IM); d8 P4 removal + 0.5 mg of estradiol cypionate (EC) + 150 [micro]g of cloprostenol + 400 IU of equine chorionic gonadotropin (eCG); in d10 TAI was proceeded; GDES (DES group; n = 60) the same as GNDES + 1.0 mg (IM) DES acetate in TAI day; GDES6 (DES applied 6 hours before TAI, n = 57) the same as GDES, but DES injected 6 hours before TAI. The pregnancy rate (PR) in TAI and at the end of the breeding season (BS) was respectively 40.6; 53.3; 43.8% and 72.9; 81.7; 70.2% in GNDES, GDES and GDES6. In conclusion, the DES brought an indicative of improvement in the PR for TAI, in the treated groups (3.2 to 12.7 % more) than control, however without significance; the BCS, open days and the reproductive status of anestrous or cyclicality, did not influenced the PR in TAI at 60 days or at the end of the BS.