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Vertebrate reproductive science and technology
REVIEW

Not just a number: effect of age on fertility, pregnancy and offspring vigour in thoroughbred brood-mares

Charles F. Scoggin
+ Author Affiliations
- Author Affiliations

Claiborne Farm, PO Box 150, Paris, KY 40362, USA. Email: cscoggin@claibornefarm.com

Reproduction, Fertility and Development 27(6) 872-879 https://doi.org/10.1071/RD14390
Submitted: 13 October 2014  Accepted: 17 February 2015   Published: 19 March 2015

Abstract

Advancing age can adversely affect a thoroughbred brood-mare’s reproductive efficiency and influence the commercial and athletic potential of her progeny. Causes for the decline in fertility include decreased oocyte and embryo quality, anatomical defects and endometrial degeneration. In addition, evidence exists that as the age of a dam increases, her foals will be at increased risk of morbidity and mortality during the neonatal period. Health issues can have lasting and deleterious effects on surviving foals, including decreased sale value and reduced athletic performance. The purpose of this review is to evaluate the association between mare age, fertility and offspring vigour in thoroughbred horses.

Additional keywords: maternal age, offspring health, subfertility.


References

Allen, W. R. (1993). Proceedings of the John P. Hughes International Workshop on Equine Endometritis. Equine Vet. J. 25, 184–193.

Allen, W. R., Brown, L., Wright, M., and Wilsher, S. (2007). Reproductive efficiency of Flatrace and National Hunt thoroughbred mares and stallions in England. Equine Vet. J. 39, 438–445.
Reproductive efficiency of Flatrace and National Hunt thoroughbred mares and stallions in England.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2srovFyntA%3D%3D&md5=0d152f353e184f1d73221ddf392a21cbCAS | 17910269PubMed |

Baker, C. B., Little, T. V., and McDowell, K. J. (1993). The live foaling rate per cycle in mares. Equine Vet. J. Suppl. 25, 28–30.

Ball, B. A. (2011). Embryonic loss. In ‘Equine Reproduction’, 2nd edn. (Eds A. O. McKinnon, E. L. Squires, W. E. Vaala and D. D. Varner.) pp. 2327–2336. (Wiley-Blackwell: Ames, IA.)

Ball, B. A., Little, T. V., Weber, J. A., and Woods, G. L. (1989). Survival of Day 4 embryos from young, normal mares and aged, subfertile mares after transfer to normal recipient mares. J. Reprod. Fertil. 85, 187–194.
Survival of Day 4 embryos from young, normal mares and aged, subfertile mares after transfer to normal recipient mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL1M7isFCqsQ%3D%3D&md5=d13e755be6289e58a4c2554ff0ed42eaCAS | 2915352PubMed |

Barron, J. K. (1995). The effect of maternal age and parity on the racing performance of thoroughbred horses. Equine Vet. J. 27, 73–75.
The effect of maternal age and parity on the racing performance of thoroughbred horses.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK2M3pt12gsQ%3D%3D&md5=814e0950ee15b50a6f34f7324030df90CAS | 7774552PubMed |

Bosh, K. A., Powell, D., Shelton, B., and Zent, W. (2009a). Reproductive performance measures among thoroughbred mares in central Kentucky, during the 2004 mating season. Equine Vet. J. 41, 883–888.
Reproductive performance measures among thoroughbred mares in central Kentucky, during the 2004 mating season.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3c3lsFSrsA%3D%3D&md5=d86ca97b03e9e66f112526cc9e575b5aCAS | 20383986PubMed |

Bosh, K. A., Powell, D., Neibergs, J. S., Shelton, B., and Zent, W. (2009b). Impact of reproductive efficiency over time and mare financial value on economic returns among thoroughbred mares in central Kentucky. Equine Vet. J. 41, 889–894.
Impact of reproductive efficiency over time and mare financial value on economic returns among thoroughbred mares in central Kentucky.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3c3lsFSrsQ%3D%3D&md5=83fcc307fb46a2c0e2cba75004543d3aCAS | 20383987PubMed |

Bracher, V., Mathias, S., and Allen, W. R. (1996). Influence of chronic degenerative endometritis (endometrosis) on placental development in the mare. Equine Vet. J. 28, 180–188.
Influence of chronic degenerative endometritis (endometrosis) on placental development in the mare.Crossref | GoogleScholarGoogle Scholar |

Bradecamp, E. A. (2011). Pneumovagina. In ‘Equine Reproduction’, 2nd edn. (Eds A. O. McKinnon, E. L. Squires, W. E. Vaala and D. D. Varner.) pp. 2537–2544. (Wiley-Blackwell: Ames, IA.)

Brinsko, S. P., Ball, B. A., Miller, P. G., Thomas, P. G. A., and Ellington, J. E. (1994). In vitro development of Day 2 embryos obtained from young, fertile mares and aged, subfertile mares. J. Reprod. Fertil. 102, 371–378.
In vitro development of Day 2 embryos obtained from young, fertile mares and aged, subfertile mares.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXjtFyns70%3D&md5=131e4d280580a57364b2f0e0f953c760CAS | 7861390PubMed |

Brück, I., Anderson, G. A., and Hyland, J. H. (1993). Reproductive performance of thoroughbred mares on six commercial stud farms. Aust. Vet. J. 70, 299–303.
Reproductive performance of thoroughbred mares on six commercial stud farms.Crossref | GoogleScholarGoogle Scholar | 8216096PubMed |

Buzby, J. C., and Jessup, E. L. (1994). The relative impact of macroeconomic and yearling-specific variables in determining thoroughbred yearling price. Appl. Econ. 26, 1–8.
The relative impact of macroeconomic and yearling-specific variables in determining thoroughbred yearling price.Crossref | GoogleScholarGoogle Scholar |

Carnevale, E. M., and Ginther, O. J. (1995). Defective oocytes as a cause of subfertility in old mares. Biol. Reprod. Mono. 1, 209–214.

Carnevale, E. M., Griffin, P. G., and Ginther, O. J. (1993). Age-associated subfertility before entry of embryos into the uterus of mares. Equine Vet. J. 25, 31–35.
Age-associated subfertility before entry of embryos into the uterus of mares.Crossref | GoogleScholarGoogle Scholar |

Carnevale, E. M., Uson, M., Bozzola, J. J., King, S. S., Schmitt, S. J., and Gates, H. D. (1999). Comparison of oocytes from young and old mares with light and electron microscopy. Theriogenology 51, 299.
Comparison of oocytes from young and old mares with light and electron microscopy.Crossref | GoogleScholarGoogle Scholar |

Carnevale, E. M., Squires, E. L., Maclellan, L. J., Alvarenga, M. A., and Scott, T. J. (2001). Use of oocyte transfer in a commercial breeding program for mares with reproductive abnormalities. J. Am. Vet. Med. Assoc. 218, 87–91.
Use of oocyte transfer in a commercial breeding program for mares with reproductive abnormalities.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3M7hs1KmtA%3D%3D&md5=79781b348e1b07456dbf28d804fe3917CAS | 11149722PubMed |

Carnevale, E. M., Coutinho da Silva, M. A., Panzani, D., Stokes, J. E., and Squies, E. L. (2005). Factors affecting the success of oocyte transfer in a clinical program for subfertile mares. Theriogenology 64, 519–527.
Factors affecting the success of oocyte transfer in a clinical program for subfertile mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2MzmslKntQ%3D%3D&md5=4a8ee6d69983f360f32d45bee9ae3150CAS | 15950272PubMed |

Caslick, E. A. (1937). The vulva and the vulvo–vaginal orifice and its relation to genital health of the thoroughbred mare. Cornell Vet. 27, 178–187.

Chezum, B., and Wimmer, B. (1997). Roses or lemons: adverse selection in the market for thoroughbred yearlings. Rev. Econ. Stat. 79, 521–526.
Roses or lemons: adverse selection in the market for thoroughbred yearlings.Crossref | GoogleScholarGoogle Scholar |

Commer, M. (1990). The effect of non-phenotypic data on thoroughbred prices in the mid-Atlantic market. Prof. Anim. Sci. 7, 18–24.

Consignors and Commercial Breeders Association (2007). Myth #3: foals out of older mares. In: ‘Buying Sales Yearlings: Plain and Simple’. (Eds R. Manseau.) pp. 24–25. (The Conignors and Commercial Breeders Association: Lexington, KY.)

Kentucky Horse Council (2013). ‘2012 Kentucky Equine Survey.’ (University of Kentucky Ag Equine Programs: Lexington, KY.)

Dink, D. (1990). Advantages of a February foal. Thoroughbred Times May 4, 28–32.

Elliott, C., Morton, J., and Chopin, J. (2009). Factors affecting foal birth weight in thoroughbred horses. Theriogenology 71, 683–689.
Factors affecting foal birth weight in thoroughbred horses.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD1M%2Fpt1yjtA%3D%3D&md5=d8ca4e36f283a70edae2147e3ff25332CAS | 18980778PubMed |

Finocchio, E. J. (1985). Race performance and its relationship to birthrank and maternal age – I. In: ‘Proceedings From the 31st Annual Convention of the American Association of Equine Practitioners’. pp. 571–577. (AAEP: Lexington, KY.)

Ginther, O. J. (1993). Reproductive efficiency. In ‘Reproductive Biology of the Mare: Basic and Applied Aspects’, 2nd edn. (Ed. O. J. Ginther.) pp. 499–562. (Equiservices Publishing: Cross Plains, WI.)

Hemberg, E., Lundeheim, N., and Einarsson, S. (2004). Reproductive performance of thoroughbred mares in Sweden. Reprod. Domest. Anim. 39, 81–85.
Reproductive performance of thoroughbred mares in Sweden.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2c7ntlClsg%3D%3D&md5=71657391b60592b72ce327bce1665340CAS | 15065988PubMed |

Hemberg, E., Lundeheim, N., and Einarsson, S. (2005). Retrospective study on vulvar conformation in relation to endometrial cytology and fertility in thoroughbred mares. J. Vet. Med. A Physiol. Pathol. Clin. Med. 52, 474–477.
Retrospective study on vulvar conformation in relation to endometrial cytology and fertility in thoroughbred mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2MrptV2guw%3D%3D&md5=ecf296f5a76fe0d136490ede6b6fa839CAS | 16268960PubMed |

Hutton, C. A., and Meacham, T. N. (1968). Reproductive efficiency on Fourteen Horse Farm. J. Anim. Sci. 27, 434–438.
| 1:STN:280:DyaF1c7pvVOrtw%3D%3D&md5=7386a63e5ddfaf546db65e3520bbde85CAS | 5646343PubMed |

Kenney, R. M. (1978). Cyclic and pathologic changes of the mare endometrium as detected by biopsy, with a note on early embryonic death. J. Am. Vet. Med. Assoc. 172, 241–262.
| 1:STN:280:DyaE1c%2FosleisA%3D%3D&md5=89b8a5f38b341d5c5720d9d5b1562f81CAS | 621166PubMed |

Lema, J.-A. S., and Finocchio, E. J. (1985). Race performance and its relationship to birthrank and maternal age – II. In: ‘Proceedings From the 31st Annual Convention of the American Association of Equine Practitioners’. pp. 577–578. (AAEP: Lexington, KY.)

Maynard, L. J., and Stoeppel, K. M. (2007). Hedonic price analysis of thoroughbred broodmares in foal. J. Agribusiness 25, 181–195.

Morley, P. S., and Townsend, G. G. (1997). A survey of reproductive performance in thoroughbred mares and morbidity, mortality and athletic potential of their foals. Equine Vet. J. 29, 290–297.
A survey of reproductive performance in thoroughbred mares and morbidity, mortality and athletic potential of their foals.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2cvjtlCltQ%3D%3D&md5=f554e170e7335e2c9a37769a46c55db9CAS | 15338910PubMed |

Morris, L. H. A., and Allen, W. R. (2002). Reproductive efficiency of intensively managed thoroughbred mares in Newmarket. Equine Vet. J. 34, 51–60.
Reproductive efficiency of intensively managed thoroughbred mares in Newmarket.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD38%2Fptlequg%3D%3D&md5=f62eba87f368be07328828214db13cd5CAS |

Nagaoka, S. I., Hassold, T. J., and Hunt, P. A. (2012). Human aneuploidy: mechanism and new insights into an age-old problem. Nat. Rev. Genet. 13, 493–504.
Human aneuploidy: mechanism and new insights into an age-old problem.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xos12ht78%3D&md5=28caef674a759838fb86d2fae328c48aCAS | 22705668PubMed |

Nath, L. C. (2010). Reproductive efficiency of thoroughbred and standardbred horses in north-east Victoria. Aust. Vet. J. 88, 169–175.
Reproductive efficiency of thoroughbred and standardbred horses in north-east Victoria.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3cvmsFahsQ%3D%3D&md5=b797d160dd7f460bdd1d64addca33750CAS | 20529022PubMed |

Nath, L. C. (2011). Reproductive efficiency. In: ‘Equine Reproduction’, 2nd edn. (Eds A. O. McKinnon, E. L. Squires, W. E. Vaala and D. D. Varner.) pp. 2779–2789. (Wiley-Blackwell: Ames, IA.)

Neibergs, J. S. (2001). A hedonic price analysis of thoroughbred broodmare characteristics. Agribusiness 17, 299–314.
A hedonic price analysis of thoroughbred broodmare characteristics.Crossref | GoogleScholarGoogle Scholar |

Pascoe, R. R. (1979). Observations on the length and the angle of declination of the vulva and its relation to fertility in the mare. J. Reprod. Fertil. Suppl. 27, 299–305.
| 289804PubMed |

Rambags, B. P. B., van Boxtel, D. C. J., Tharasanit, T., Lenstra, J. A., Colenbrander, B., and Stout, T. A. E. (2006). Oocyte mitochondrial degeneration during reproductive ageing in the mare. Havemeyer Found. Monogr. Ser. 18, 25–27.

Rambags, B. P., van Boxtel, D. C. J., Tharasanit, T., Lenstra, J. A., Colenbrander, B., and Stout, T. A. E. (2014). Advancing maternal age predisposes to mitochondrial damage and loss during maturation of equine oocytes in vitro. Theriogenology 81, 959–965.
Advancing maternal age predisposes to mitochondrial damage and loss during maturation of equine oocytes in vitro.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXjsF2gurc%3D&md5=ad6e368a68b30907f0750967a230eb4dCAS | 24576711PubMed |

Ricketts, S. W., and Alonso, S. (1991). The effect of age and parity on the development of chronic endometrial disease. Equine Vet. J. 23, 189–192.
The effect of age and parity on the development of chronic endometrial disease.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK3MzlslSjtg%3D%3D&md5=395578074e85f381d2e6696223f70ab8CAS | 1884699PubMed |

Robbins, M., and Kennedy, P. E. (2001). Buyer behavior in a regional thoroughbred yearling market. Appl. Econ. 33, 969–977.
Buyer behavior in a regional thoroughbred yearling market.Crossref | GoogleScholarGoogle Scholar |

Rogers, B. (2014). Ageism at yearling sales. Bluebloods September, 37.

Sanchez, L. C., Giguere, S., and Lester, G. D. (2008). Factors associated with survival of neonatal foals with bacteremia and racing performance of surviving thoroughbreds: 423 cases (1982–2007). J. Am. Vet. Med. Assoc. 233, 1446–1452.
Factors associated with survival of neonatal foals with bacteremia and racing performance of surviving thoroughbreds: 423 cases (1982–2007).Crossref | GoogleScholarGoogle Scholar | 18980499PubMed |

Tapp, I. (2014). Young mares. Blood-Horse 34, 22–23.

Wilsher, S., and Allen, W. R. (2003). The effects of maternal age and parity on placental and fetal development in the mare. Equine Vet. J. 35, 476–483.
The effects of maternal age and parity on placental and fetal development in the mare.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3szkt12rtQ%3D%3D&md5=f2a40707bc2fd404f1f85b0b183e2b2aCAS | 12875326PubMed |

Wilsher, S., Allen, W. R., and Wood, J. L. N. (2006). Factors associated with failure of thoroughbred horses to train and race. Equine Vet. J. 38, 113–118.
Factors associated with failure of thoroughbred horses to train and race.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD287kslCluw%3D%3D&md5=9248236975e5354ef5e62080684b71aeCAS | 16536379PubMed |