Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Alternative low doses and routes of administering a prostaglandin F2α analogue to induce luteolysis in Nelore cows | J. Vet. Sci. 2006 7 4 387-390 JOURNAL OF Veterinary Science Alternative low doses and routes of administering a prostaglandin F2a analogue to induce luteolysis in Nelore cows Cezinande Meira Valsair Matos Pessoa João Carlos Pinheiro Ferreira Gustavo Henrique M. Araujo Mari III M. Gioso Sony Dimas Bicudo Eunice Oba Cassia Orlandi Department of Animal Reproduction and Veterinary Radiology School ofVeterinary Medicine and Animal Science Sao Paulo State University Botucatu Sao Paulo 18618-000 Brazil The present study was conducted in order to verify the efficacy of lower doses and alternative routes of a prostaglandin F2a analogue luprostiol PGF for the induction of luteofysis and the precipitation of estrus in nonlactating Nelore cows Bos taurus indicus . A conventional dose 15 mg of PGF was compared to doses lower than the conventional dose which ranges from 10 to 50 that were administered intramuscularly IM intravulvosubmucosally IVSM or in the Bai-hui acupuncture site located within the lumbosacral area. The cows were administered PGF 8 day after estrus in the presence of a corpus luteum and randomly assigned to the following groups G1 positive control 15 mg IM n 23 G2 7J5 mg IM n 23 G3 mg IM n 24 G4 mg IVSM n 25 G5 mg Bai-hui acupoint n 24 and G6 mg Bai-hui acupoint n 25 . The results indicated that 50 of a conventional dose of PGF mg resulted in a complete luteal regression plasma progesterone 1 ng ml at Hour 48 and hastened estrus regardless of whether or not PGF was administered IM or IVSM. Comparatively 10 or 25 of the conventional dose even when administered to the Bai-hui acupoint resulted in an initial reduction in the concentration of progesterone at Hour 24 followed by an increase observed at Hour 48. In conclusion 25 of a conventional PGF dose administered via the Bai-hui acupoint proved inadequate to induce a complete luteal regression whereas 50 of a conventional dose administered IM or IVSM was found to be the minimal dose .
