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 DA 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: markb@thevets.co.nz
Reproduction, Fertility and Development 22(1) 126-131 https://doi.org/10.1071/RD09225
Published: 8 December 2009
Abstract
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 | GoogleScholarGoogle Scholar |
Boland, M. P. (2005). Impact of current management practices on embryo survival in the modern dairy cow. Irish Vet J. 58, 31–36.
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.
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 | GoogleScholarGoogle Scholar | PubMed | CAS |
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 |
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 |
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 | GoogleScholarGoogle Scholar | PubMed |