Dissemin is shutting down on January 1st, 2025

Published in

CSIRO Publishing, Reproduction, Fertility and Development, 2(26), p. 235, 2014

DOI: 10.1071/rd12295

Links

Tools

Export citation

Search in Google Scholar

Reductions in the number of mid-sized antral follicles are associated with markers of premature ovarian senescence in dairy cows

This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Green circle
Preprint: archiving allowed
Green circle
Postprint: archiving allowed
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

High-producing dairy cows are subfertile; however, the mechanisms responsible for the decreased fertility are unknown. The aim of the present study was to test the hypothesis that culled dairy cows (4–8 years old) characterised by ‘Lo’ ovaries (i.e. those with <10 mid-antral follicles) are affected by premature ovarian senescence. Cows in which both ovaries were ‘Lo’ ovaries represented 5% of the total population analysed, and exhibited reduced ovarian size (P < 0.001) and increased perifollicular stroma (P < 0.05) compared with age-matched controls (i.e. cows in which both ovaries had >10 mid-antral follicles; ‘Hi’ ovaries). The total number of follicles, including healthy and atretic primordial, primary, secondary and small antral follicles, was lower in Lo ovaries (P < 0.01). Interestingly, the primordial follicle population in Lo ovaries was lower (P < 0.05) than in the control. Finally, the follicular fluid of mid-antral follicles from Lo ovaries had reduced oestradiol and anti-Müllerian hormone levels (P < 0.05), but increased progesterone concentrations (P < 0.05). Together, these data account for the reduced fertility of cows with Lo ovaries and are in agreement with previous observations that oocytes isolated from Lo ovaries have reduced embryonic developmental competence. Cows with a specific Lo ovary condition may represent a suitable model to address the causes of low fertility in high-yielding dairy cows, as well as the condition of premature ovarian aging in single-ovulating species.