title: Hormone supplementation protocol using estradiol benzoate and long-acting progesterone is efficient in maintaining pregnancy of anovulatory recipient mares during autumn transitional phase.
abstract: The present research sought to determine whether the administration of estradiol benzoate and long-acting progesterone to anovulatory recipient mares could maintain the pregnancy after embryo transfer during the autumn transitional phase. Recipient mares (n = 40) received the hormonal supplementation (treated group) whereas the other 36 served as a control. The control group consisted of mares having typical estrous cycles with ovulations, development of a viable corpus luteum and received one transferred embryo 5 days after ovulation. Hormonal administrations in the treated group started 8 days before the embryo transfer. During the first 3 days, the mares received estradiol benzoate (5 mg the first day, 3 mg the second day and 2 mg the third day). At Day 5 subsequent to ovulation, the mares received one administration of 1500 mg long-acting progesterone, and the same treatments occurred at the day of embryo transfer. Afterwards, treated mares also received 1500 mg long-acting progesterone every 7 days until 120 days of gestation. For both control and treated groups, the recipient mares were classified as acceptable, marginally acceptable or unacceptable for embryo transfer, and the embryo quality was also determined. The pregnancy diagnosis in recipient mares was made at Days 13, 30 and 60 of pregnancy. While the pregnancy rate was greater (P < 0.05) in the treated than in the control group, the recipient classification did not influence pregnancy rates. In conclusion, pregnancy in anovulatory recipient mares during the autumn transitional phase can be achieved when estradiol benzoate and progesterone are administered.
authors.affiliation: Center for Equine Reproduction and Medicine at South Minas Gerais, Nepomuceno, Minas Gerais, Brazil.
authors.forename: Jorge H V
authors.initials: JH
authors.lastname: Botelho
authors.affiliation: Center for Equine Reproduction and Medicine at South Minas Gerais, Nepomuceno, Minas Gerais, Brazil.
authors.forename: Gabriela O
authors.initials: GO
authors.lastname: Pessoa
authors.affiliation: Unit of Physiology and Pharmacology, Department of Veterinary Medicine, Federal University of Lavras, Minas Gerais, Brazil; Unit of Animal Reproduction, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Barcelona, Spain. Electronic address: lgvetp@yahoo.com.br.
authors.forename: Luiz G P
authors.initials: LG
authors.lastname: Rocha
authors.affiliation: Unit of Animal Reproduction, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Barcelona, Spain.
authors.forename: Marc
authors.initials: M
authors.lastname: Yeste
mesh_terms: D000818:Animals; D000858:Anovulation / Q000188:drug therapy* / Q000662:veterinary; D001947:Breeding / Q000379:methods; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004624:Embryo Transfer / Q000662:veterinary*; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D005260:Female; D006736:Horses; D007315:Insemination, Artificial / Q000662:veterinary; D011247:Pregnancy; D011255:Pregnancy Maintenance / Q000187:drug effects*; D011270:Pregnancy, Animal / Q000187:drug effects; D011374:Progesterone / Q000008:administration & dosage*; D012621:Seasons; D016896:Treatment Outcome
chemical_list: D003692:Delayed-Action Preparations; C074283:estradiol 3-benzoate; D011374:Progesterone; D004958:Estradiol
keywords: Autumn transitional phase; Embryo transfer; Equine; Estradiol benzoate; Progesterone; Recipient mares