tailieunhanh - Báo cáo khoa học: " Endocrine and Ovarian Changes in Response to the Ram Effect in Medroxyprogesterone Acetate-primed Corriedale Ewes"

Tuyển tập các báo cáo nghiên cứu về bệnh thú y được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành thú y đề tài: Endocrine and Ovarian Changes in Response to the Ram Effect in Medroxyprogesterone Acetate-primed Corriedale Ewes . | Acta vet. scand. 2005 46 33-44. Endocrine and Ovarian Changes in Response to the Ram Effect in Medroxyprogesterone Acetate-primed Corriedale Ewes During the Breeding and Nonbreeding Season By R. Ungerfelda b B. Carbajala E. Rubianesc and M. Forsberg aDepartamento de Fisiologia Facultad de Veterinaria Lasplaces 1550 Montevideo 11600 Uruguay bCentre for Reproductive Biology Department of Clinical Chemistry Faculty of Veterinary Medicine Swedish University of Agricultural Sciences Uppsala Sweden and cDepartamento de Producción Animal Facultad de Agronomía Montevideo Uruguay. Ungerfeld R Carbajal B Rubianes E Forsberg M Endocrine and ovarian changes in response to the ram effect in medroxyprogesterone acetate-primed corriedale ewes during the breeding and nonbreeding-season. Acta vet. scand. 2005 46 33-44. - Two experiments were performed to determine the endocrine and ovarian changes in medroxyprogesterone acetate MAP -primed ewes after ram introduction. Experiment 1 was performed during the mid-breeding season with 71 ewes primed with an intravagi-nal MAP sponge for 12 days. While the control C ewes n 35 were in permanent contact with rams the ram effect RE ewes n 36 were isolated for 34 days prior to contact with rams. At sponge withdrawal all ewes were joined with eight sexually experienced marking Corriedale rams and estrus was recorded over the next 4 days. The ovaries were observed by laparoscopy 4-6 days after estrus. Four weeks later pregnancy was determined by transrectal ultrasonography. In eight ewes from each group ovaries were ultrasonographically scanned FSH LH and estradiol-17B were measured every 12 hours until ovulation or 96 hours after estrus. The response to the rams was not affected by the fact that ewes had been kept or not in close contact with males before teasing. No differences were found in FSH LH estradiol-17B concentrations growth of the ovulatory follicle onset of estrus ovulation rate or pregnancy rate. Experiment 2 was performed with 14