Reproduction, Fertility and Development Reproduction, Fertility and Development Society
Vertebrate reproductive science and technology

Use of equine chorionic gonadotrophin in synchronised AI of seasonal-breeding, pasture-based, anoestrous dairy cattle

M. A. Bryan A E , G. A. Bó B , C. Heuer C and F. R. Emslie D
+ Author Affiliations
- Author Affiliations

A VetSouth Ltd, PO Box 12, Winton, Southland, New Zealand.

B Instituto de Reproducción Animal Córdoba (IRAC), 2 Univ. Católica de Córdoba, 3UNICEN, 4Ag. Cba. Ciencia, Córdoba, Argentina.

C Epicentre, Institute of Veterinary Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand.

D Bomac Laboratories Ltd, PO Box 76-369, Manakau City, Auckland, New Zealand.

E Corresponding author. Email:

Reproduction, Fertility and Development 22(1) 126-131
Published: 8 December 2009


In seasonally calving dairy areas, a critical index of efficiency and profitability is the ability to maintain a short annual calving spread. In essence, this means that all cows need to conceive within 90 days of calving. Anovulatory anoestrus (AA) is a major barrier to reproductive performance under these conditions and the successful treatment of AA is an important aspect of reproductive intervention. The present paper reviews regimens used to treat AA in New Zealand and reports on a large-scale field trial investigating the effects of equine chorionic gonadotrophin (eCG) within a proven efficacious treatment protocol. The administration of eCG at the time of removal of a progesterone-releasing device in an 8-day, oestradiol benzoate (EB)-based treatment protocol increased the percentage of cows in calf after 7 and 28 days of breeding. The interaction between cow age and treatment with eCG was significant, with cows over 5 years of age having higher conception rates (P = 0.002) and 7 day in-calf rates (P = 0.002) than cows on a standard 8-day treatment protocol without eCG. The addition of eCG to a standard 8-day EB/progesterone protocol can improve reproductive success in seasonally calving AA dairy cows.

Additional keywords: anovulatory anoestrus, oestradiol benzoate, progesterone.


Baruselli, P. , Reis, E. , Marques, M. O. , Nasser, L. , and Bo, G. A. (2004). The use of hormonal treatments to improve reproductive performance of anestrous beef cattle in tropical climates. Anim. Reprod. Sci. 82–83, 479–486.
CrossRef |

Bo G. A., Cutaia L., Chesta P., Balla E., Picinato D., et al. (2005). Application of fixed-time artificial insemination and embryo transfer programs in beef cattle operations. In ‘Proceedings of the Joint Convention of AETA and CETA, Minneapolis, MN, USA’. (Ed. The American Embryo Transfer Association.) pp. 37–59. (AETA: Savoy, IL.)

Boland, M. P. (2005). Impact of current management practices on embryo survival in the modern dairy cow. Irish Vet J. 58, 31–36.

Bryan M. A., Bo G. A., Emslie R., and Mapletoft R. J. (2009). Efecto del tratamiento con ecg en vacas lecheras en anestro tratadas con protocolos con GnRH y dispositivos con progesterona por 6 o 7 dias. In ‘Proceedings of the VIII Simposio Internacional de Reproduccion Animal, Cordoba, Argentina’. (Eds D. Moreno and G. A. Bo.) Section 7 abstract 4. (Instituto de Reproduccion Animal Cordoba: Cordoba.) [Abstract]

Chagas, L. M. , Gore, P. J. S. , Sheahan, A. J. , Lee, J. M. , Watkins, K. A. , Aspin, P. W. , and Roche, J. R. (2006). Diet or strain: Effects on postpartum anovulatory interval in dairy cows. Proc. N. Z. Soc. Anim. Prod. 66, 339–343.

Cutaia L., Tribulo R., Moreno D., and Bo G. A. (2003). Pregnancy rate in lactating beef cows treated with progesterone-releasing devices, estradiol benzoate and equine chorionic gonadotropin (eCG). Theriogenology 59, 216. [Abstract]

de Medeiros Bastos, G. , Brenner, R. H. , Willke, F. W. , Neves, J. P. , de Oliveira, J. F. C. , Bragança, J. F. M. , Machado, S. A. , Porciúncula, P. M. , and Gonçalves, P. B. D. (2004). Hormonal induction of ovulation and artificial insemination in suckled beef cows under nutritional stress. Theriogenology 62, 847–853.
CrossRef | PubMed | CAS |

Fielden, E. D. , Macmillan, K. L. , and Watson, J. D. (1973). The anoestrus syndrome in New Zealand dairy cattle. N. Z. Vet. J. 21, 77–81.
PubMed | |  CAS |

Freedman, L. S. (1982). Tables of the number of patients required in clinical trials using the log rank test. Stat. Med. 1, 121–129.
CrossRef | PubMed | CAS |

Macdonald K. A., and Macmillan K. L. (1993). Condition score and liveweight in Jersey and Friesian cows. In ‘Proceedings of the 45th Ruakura Farmers’ Conference’. (Ed. J. Lomas.) pp. 47–50. (Dairying Research Corporation: Hamilton.)

Macmillan, K. L. (2002a). Advances in bovine theriogenology in New Zealand. 2. Breeding management and technologies for improved reproduction. N. Z. Vet. J. 50(Suppl.), 74–80.
PubMed | |  CAS |

Macmillan, K. L. (2002b). Advances in bovine theriogenology in New Zealand. 1. Pregnancy, parturition and the postpartum period. N. Z. Vet. J. 50(Suppl.), 67–73.
PubMed | |  CAS |

Macmillan, K. L. , and Peterson, A. J. (1993). A new intravaginal progesterone releasing device in cattle (CIDR-B) for oestrous synchronisation, increasing pregnancy rates and the treatment of postpartum anoestrum. Anim. Reprod. Sci. 33, 1–25.
CrossRef |

Macmillan, K. L. , Lean, I. J. , and Westwood, C. T. (1996). A review of relationships involving milk yield, energy balance, blood metabolites and reproductive performance in high yielding dairy cows. Aust. Vet. J. 73, 141–147.
CrossRef | PubMed | CAS |

Mapletoft, R. J. , Bo, G. A. , and Baruselli, P. (2009). Control of ovarian function for assisted reproductive technologies in cattle. Anim. Reprod. 6, 114–124.

McDougall, S. (2001). Reproductive performance of anovulatory anoestrous postpartum dairy cows following treatment with two progesterone and oestradiol benzoate-based protocols, with or without resynchrony. N. Z. Vet. J. 49, 187–194.
PubMed | |  CAS |

McDougall, S. (2003). Resynchrony of previously anoestrous cows and treatment of cows not detected in oestrus that had a palpable corpus luteum with prostaglandin F2α. N. Z. Vet. J. 51, 117–124.
PubMed | |  CAS |

McDougall S. (2008). Effects of treatment of ‘not-detected in oestrus’ cows with gonadotrophin releasing hormone, prostaglandin and progesterone. In ‘Proceedings of the Society of Dairy Cattle Vets’. (Ed. T. J. Parkinson.) pp. 35–50. (VetLearn: Palmerston North, New Zealand.)

Morris, C. A. , and Day, A. M. (1994). The relationship between estimates of ovarian size in live cattle and subsequent measurements post mortem. N. Z. Vet. J. 42, 185–186.
PubMed | |  CAS |

Peters, M. W. , and Pursley, J. R. (2002). Fertility of lactating dairy cows treated with ovsynch after presynchronization injections of PGF2α and GnRH. J. Dairy Sci. 85, 2403–2406.
PubMed | |  CAS |

Pursley, J. R. , Kosorok, M. R. , and Wiltbank, M. C. (1997). Reproductive management of lactating dairy cows using synchronization of ovulation. J. Dairy Sci. 80, 301–306.
PubMed | |  CAS |

Rhodes, F. M. , Clark, B. A. , Nation, D. P. , Taufa, V. K. , Day, M. L. , Macmillan, K. L. , and McDougall, S. (1998). Treatment of postpartum anoestrus in New Zealand dairy cows with progesterone and oestradiol benzoate. Proc. 20th World Buiatrics Congr. 2, 607–612.

Rhodes, F. M. , McDougall, S. , Morgan, S. R. , and Verkerk, G. (2001). Supplementing treated anoestrous cows with progesterone does not increase conception rates. N. Z. Vet. J. 49, 8–12.
PubMed | |  CAS |

Rhodes, F. M. , McDougall, S. , Burke, C. R. , Verkerk, G. A. , and Macmillan, K. L. (2003). Treatment of cows with an extended postpartum anoestrous interval. J. Dairy Sci. 86, 1876–1894.
PubMed | |  CAS |

Souza, A. H. , Viechnieski, S. , Lima, F. A. , Silva, F. F. , Araújo, R. , Bó, G. A. , Wiltbank, M. C. , and Baruselli, P. S. (2009). Effects of equine chorionic gonadotropin and type of ovulatory stimulus in a timed-AI protocol on reproductive responses in dairy cows. Theriogenology 72, 10–21.
CrossRef | CAS | PubMed |

Small, J. A. , Colazo, M. G. , Kastelic, J. P. , and Mapletoft, R. J. (2009). Effects of progesterone presynchronization and eCG on pregnancy rates to GnRH-based, timed-AI in beef cattle. Theriogenology 71, 698–706.
CrossRef | PubMed | CAS |

Smith, J. F. , and Macmillan, K. L. (1978). The applied and economic aspects of oestrus synchronisation in cattle. N. Z. Vet. J. 26, 173–175.
PubMed | |  CAS |

Soumano, K. , Lussier, J. G. , and Price, C. A. (1998). Levels of messenger RNA encoding ovarian receptors for FSH and LH in cattle during superovulation with equine chorionic gonadotrophin versus FSH. J. Endocrinol. 156, 373–378.
CrossRef | CAS | PubMed |

Stewart, F. , and Allen, W. (1979). The binding of FSH, LH and PMSG to equine gonadal tissues. J. Reprod. Fertil. Suppl. 27, 431–440.
PubMed |

Veneranda G., Filippi L., Racca D., Romero G., Balla E., Cutaia L., and Bó G. A. (2006). Pregnancy rates in dairy cows treated with intravaginal progesterone devices and different fixed-time AI protocols. Reprod. Fertil. Dev. 18, 118. [Abstract]

Veneranda G., Filippi L., Racca D., Cutaia L., and Bó G. A. (2008). Pregnancy rates in dairy cows treated with intravaginal progesterone devices and GnRH or estradiol benzoate and eCG. Reprod. Fertil. Dev. 20, 91. [Abstract]

Verkerk, G. , Taufa, V. K. , Morgan, S. , Clark, B. A. , and Macmillan, K. L. (1998). Effects of oestradiol benzoate by injection at CIDR™ insertion for the treatment of postpartum anovulatory anoestrus in dairy cows. Proc. N. Z. Soc. Anim. Prod. 58, 82–84.

Washburn, S. P. , Silvia, W. J. , Brown, C. H. , McDaniel, B. T. , and McAllister, A. J. (2002). Trends in reproductive performance in southeastern Holstein and Jersey DHI herds. J. Dairy Sci. 85, 244–251.
PubMed | |  CAS |

Xu, Z. Z. , Burton, L. J. , and Macmillan, K. L. (1997). Treatment of post-partum anoestrous dairy cows with progesterone, oestradiol and equine chorionic gonadotrophin. N. Z. Vet. J. 45, 205–207.
PubMed | |  CAS |

Zou, G. (2004). A modified poisson regression approach to prospective studies with binary data. Am. J. Epidemiol. 159(7), 702–706.
CrossRef | PubMed |

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