Register      Login
Reproduction, Fertility and Development Reproduction, Fertility and Development Society
Vertebrate reproductive science and technology
Shopping Cart: ( empty )
You are here: Home > Journals > RD > RD08121
RESEARCH ARTICLE
Contents Vol 20(8)

Effects of age on follicle and hormone dynamics during the oestrous cycle in mares

O. J. Ginther A B C , M. O. Gastal A , E. L. Gastal B , J. C. Jacob A , M. A. R. Siddiqui A and M. A. Beg B
+ Author Affiliations
- Author Affiliations

A Eutheria Foundation, Cross Plains, WI 53528, USA.

B Department of Pathobiological Sciences, University of Wisconsin, Madison, WI 53706, USA.

C Corresponding author. Email: ginther@svm.vetmed.wisc.edu

Reproduction, Fertility and Development 20(8) 955-963 https://doi.org/10.1071/RD08121
Submitted: 1 June 2008  Accepted: 3 September 2008   Published: 23 October 2008

Abstract

The effects of age (young: 5–6 years; intermediate: 10–14 years; old: ≥18 years) on follicle and hormone dynamics during an interovulatory interval (IOI; n = 46) and on preovulatory oocytes and concentrations of follicular fluid factors (n = 44) were studied in mares. Old mares were not approaching senescence, as indicated by regular lengths of the IOI (19–27 days) during the period May–October. The IOI was 1 day longer (P < 0.05) in the old group than in the two younger groups and was associated with a slower (P < 0.05) growth rate of the ovulatory follicle. The old group had diminished follicle activity, as indicated by significantly smaller and fewer follicles. Concentrations of FSH did not differ among age groups, except that the maximum concentration was greater (P < 0.05) in the old group. Concentrations of LH were greater (age × day interaction; P < 0.03) in the young group throughout the ovulatory LH surge and may have played a role in a shorter (P < 0.05) interval from maximum diameter of the preovulatory follicle to ovulation. Maximum circulating concentrations of oestradiol during the preovulatory surge were greatest (P < 0.05) in the young group. No effects of age were detected on oocyte morphology. Concentrations of ovarian steroids in preovulatory follicular fluid were not affected by the age of the mares, but concentrations of free insulin-like growth factor-1 were greater (P < 0.05) in the old group. The results indicate the importance of considering the potential confounding effects of age in experimental protocols and for considering age in the development of theriogenology programmes.

Additional keywords: gonadotropins, oestradiol, progesterone, senescence, ultrasonography.


Acknowledgements

This study was supported by the Eutheria Foundation. J. C. F. Jacob was on leave from the Department of Reproduction and Animal Evaluation, Federal Rural University of Rio de Janeiro, Rio de Janeiro, Brazil.


References

American Association of Equine Practitioners (2002). ‘Official Guide for Determining the Age of the Horse.’ (AAEP: Lexington, KY.)

Beg, M. A. , and Ginther, O. J. (2006). Follicle selection in cattle and horses: role of intrafollicular factors. Reproduction 132, 365–377.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Ginther O. J. (1995). ‘Ultrasonic Imaging and Animal Reproduction: Book 2, Horses.’ (Equiservices Publishing: Cross Plains, WI.)

Ginther, O. J. (2000). Selection of the dominant follicle in cattle and horses. Anim. Reprod. Sci. 60–61, 61–79.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Ginther O. J. (2007). ‘Ultrasonic Imaging and Animal Reproduction: Color-Doppler Ultrasonography, Book 4.’ (Equiservices Publishing: Cross Plains, WI.)

Ginther, O. J. , Gastal, E. L. , Gastal, M. O. , Bergfelt, D. R. , Baerwald, A. R. , and Pierson, R. A. (2004). Comparative study of the dynamics of follicular waves in mares and women. Biol. Reprod. 71, 1195–1201.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Jacob J. C., Gastal E. L., Gastal M. O., Carvalho G. R., Beg M. A., and Ginther O. J. (2007). Temporal relationships and repeatability of follicle diameters and hormone concentrations within individuals in mares. Reprod. Domest. Anim., in press.

Juul, A. , Bang, P. , Hertel, N. T. , Main, K. , Dalgaard, P. , Jørgensen, K. , Müller, J. , Hall, K. , and Skakkebaek, N. E. (1994). Serum insulin-like growth factor-I in 1030 healthy children, adolescents, and adults: relation to age, sex, stage of puberty, testicular size, and body mass index. J. Clin. Endocrinol. Metab. 78, 744–752.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Malhi P. S., Adams G. P., Mapletoft R. J., and Singh J. (2008). Superovulatory response in a bovine model of reproductive aging. Anim. Reprod. Sci., in press.

Malinowski, K. , Christensen, R. A. , Hafs, H. D. , and Scanes, C. G. (1996). Age and breed differences in thyroid hormones, insulin-like growth factor (IGF)-I and IGF binding proteins in female horses. J. Anim. Sci. 74, 1936–1942.
| PubMed | Siddiqui M. A. R., Gastal E. L., Ju J. C., Gastal M. O., Beg M. A., and Ginther O. J. (2008a). Nuclear configuration, spindle morphology and cytoskeletal organization of in vivo maturating horse oocytes. Reprod. Domest. Anim., in press.

Siddiqui M. A. R., Gastal E. L., Gastal M. O., Beg M. A., and Ginther O. J. (2008b). Effect of hCG in the presence of hCG antibodies on the follicle, hormone concentrations, and oocyte in mares. Reprod. Domest. Anim., in press.

Singh, J. , Domínguez, M. , Jaiswal, R. , and Adams, G. P. (2004). A simple ultrasound test to predict the superstimulatory response in cattle. Theriogenology 62, 227–243.
| Crossref | GoogleScholarGoogle Scholar | PubMed |

Soules, M. R. , Sherman, S. , Parrott, E. , Rebar, R. , Santoro, N. , Utian, W. , and Woods, N. (2001). Executive summary: Stages of Reproductive Aging Workshop (STRAW). Fertil. Steril. 76, 874–878.
| Crossref | GoogleScholarGoogle Scholar | PubMed |

Spicer, L. J. , Santiago, C. A. , Davidson, T. R. , Bridges, T. S. , and Chamberlain, C. S. (2005). Follicular fluid concentrations of free insulin-like growth factor (IGF)-I during follicular development in mares. Domest. Anim. Endocrinol. 29, 573–581.
| Crossref | GoogleScholarGoogle Scholar | PubMed |

Thomas, F. H. , Campbell, B. K. , Armstrong, D. G. , and Telfer, E. E. (2007). Effects of IGF-I bioavailability on bovine preantral follicular development in vitro. Reproduction 133, 1121–1128.
| Crossref | GoogleScholarGoogle Scholar | PubMed |

Wesson, J. A. , and Ginther, O. J. (1981). Influence of season and age on reproductive activity in pony mares on the basis of a slaughterhouse survey. J. Anim. Sci. 52, 119–129.
| PubMed |

Zenzes, M. T. , Reed, T. E. , and Casper, R. F. (1997). Effects of cigarette smoking and age on the maturation of human oocytes. Hum. Reprod. 12, 1736–1741.
| Crossref | GoogleScholarGoogle Scholar | PubMed |