RESUMO
This study evaluated the association between plasma anti-Mullerian hormone (AMH) concentration and fertility in Nelore (Bos indicus) heifers submitted to timed artificial insemination (TAI). At the onset of the synchronization protocol, heifers (n = 289) received a subcutaneous P4 ear implant (3 mg) and 2 mg of oestradiol benzoate. Eight days later, the P4 implant was removed and 0.5 mg of oestradiol cypionate, prostaglandin (0.265 mg, i.m.) and equine chorionic gonadotropin (300 UI, i.m.) was administered, and TAI was performed 48 hr after ear implant removal. Ovarian ultrasound evaluations were performed to measure number of ovarian follicles, dominant follicle size and ovulation response. Pregnancy diagnosis was performed by ultrasound 30 days after AI. Heifers with greater circulating AMH had more antral follicles, a smaller dominant follicle near timed ovulation and lower ovulation response to the timed AI protocol compared to heifers with lower circulating AMH. Although AMH and pregnancy outcome had a quadratic-shaped pattern, AMH was not significantly associated with fertility. In conclusion, heifers with lower AMH had larger follicles towards the end of the synchronization protocol and greater ovulation responses, whereas greater circulating AMH was unrelated to conception success.
Assuntos
Hormônio Antimülleriano/sangue , Bovinos/fisiologia , Folículo Ovariano/efeitos dos fármacos , Ovulação/efeitos dos fármacos , Animais , Gonadotropina Coriônica/administração & dosagem , Estradiol/administração & dosagem , Estradiol/análogos & derivados , Sincronização do Estro/métodos , Feminino , Fertilidade/fisiologia , Inseminação Artificial/veterinária , Folículo Ovariano/diagnóstico por imagem , Indução da Ovulação/métodos , Indução da Ovulação/veterinária , Gravidez , Prostaglandinas/administração & dosagem , Ultrassonografia/veterináriaRESUMO
Our expanding knowledge of ovarian function during the buffalo estrous cycle has given new approaches for the precise synchronization of follicular development and ovulation to apply consistently assisted reproductive technologies (ART). Recent synchronization protocols are designed to control both luteal and follicular function and permit fixed-time AI with high pregnancy rates during the breeding (autumn-winter) and nonbreeding (spring- summer) seasons. Additionally, allow the initiation of superstimulatory treatments at a self-appointed time and provide opportunities to do fixed-time AI in donors and fixed-time embryo transfer in recipients. However, due the scarce results of in vivo embryo recovery in superovulated buffaloes, the association of ovum pick-up (OPU) with in vitro embryo production (IVEP) represents an alternative method of exploiting the genetics of high yeld buffaloes. Nevertheless, several factors appear to be critical to OPU/IVEP efficiency, including antral follicle population, follicular diameter, environment, farm and category of donor. This review discusses a number of key points related to the manipulation of ovarian follicular growth to improve assisted reproductive technologies in buffalo.
RESUMO
Our expanding knowledge of ovarian function during the buffalo estrous cycle has given new approaches for the precise synchronization of follicular development and ovulation to apply consistently assisted reproductive technologies (ART). Recent synchronization protocols are designed to control both luteal and follicular function and permit fixed-time AI with high pregnancy rates during the breeding (autumn-winter) and nonbreeding (springsummer) seasons. Additionally, allow the initiation of superstimulatory treatments at a self-appointed time and provide opportunities to do fixed-time AI in donors and fixed-time embryo transfer in recipients. However, due the scarce results of in vivo embryo recovery in superovulated buffaloes, the association of ovum pick-up (OPU) with in vitro embryo production (IVEP) represents an alternative method of exploiting the genetics of high yeld buffaloes. Nevertheless, several factors appear to be critical to OPU/IVEP efficiency, including antral follicle population, follicular diameter, environment, farm and category of donor. This review discusses a number of key points related to the manipulation of ovarian follicular growth to improve assisted reproductive technologies in buffalo.
Assuntos
Animais , Bovinos , Búfalos/embriologia , Técnicas de Reprodução Assistida , Técnicas de Reprodução Assistida/veterinária , Transferência Embrionária/veterináriaRESUMO
Our expanding knowledge of ovarian function during the buffalo estrous cycle has given new approaches for the precise synchronization of follicular development and ovulation to apply consistently assisted reproductive technologies (ART). Recent synchronization protocols are designed to control both luteal and follicular function and permit fixed-time AI with high pregnancy rates during the breeding (autumn-winter) and nonbreeding (springsummer) seasons. Additionally, allow the initiation of superstimulatory treatments at a self-appointed time and provide opportunities to do fixed-time AI in donors and fixed-time embryo transfer in recipients. However, due the scarce results of in vivo embryo recovery in superovulated buffaloes, the association of ovum pick-up (OPU) with in vitro embryo production (IVEP) represents an alternative method of exploiting the genetics of high yeld buffaloes. Nevertheless, several factors appear to be critical to OPU/IVEP efficiency, including antral follicle population, follicular diameter, environment, farm and category of donor. This review discusses a number of key points related to the manipulation of ovarian follicular growth to improve assisted reproductive technologies in buffalo.(AU)