Maternal age influences the number of primordial follicles in the ovaries of yearling Angus heifers

Sarah C. Tenley, Renata Spuri Gomes, Shelby L. Rosasco, Emmalee J. Northrop, Jerica J.J. Rich, Anthony K. McNeel, Adam F. Summers, Jeremy R. Miles, Chadwick C. Chase, Clay A. Lents, George A. Perry, Jennifer R. Wood, Andrea S. Cupp, Robert A. Cushman

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

The number of antral follicles detectable by ultrasonography in heifers is influenced by age of the dam, because daughters of primiparous cows have fewer antral follicles than daughters of mature cows. We, therefore, hypothesized that heifers with primiparous dams would have fewer primordial follicles in their ovaries than heifers born to mature (4+ y) cows. Angus heifers (n = 464) were submitted for ultrasonographic evaluation of antral follicle number at 325, 355, and 385 d of age. Ovaries were collected from a random subset of heifers (n = 79) and processed for histological evaluation to determine number of primordial follicles. A greater percentage of heifers with primiparous dams had a corpus luteum at first ultrasonographic examination; however, a greater percentage of heifers with multiparous dams had ovulated by the start of breeding (P < 0.01). Heifers with primiparous dams had fewer antral follicles detectable by ultrasonography (P < 0.01). Heifers with primparous dams had fewer surface antral follicles on their ovaries (P < 0.01), and the number of primordial follicles per histological section was less for heifers with primiparous dams (P = 0.02). These data indicate that the lesser number of antral follicles detectable by ultrasonography in heifers with primparous dams is due to less ovarian follicle reserves. Selecting replacement heifers from mature dams may result in daughters with greater fertility and reproductive longevity; however, further research is necessary to determine if interactions between size of the ovarian follicle reserve and age at puberty influence fertility and reproductive longevity in replacement heifers.

Original languageEnglish (US)
Pages (from-to)105-112
Number of pages8
JournalAnimal Reproduction Science
Volume200
DOIs
StatePublished - Jan 2019

Keywords

  • Fetal programming
  • Heifer
  • Ovarian reserve
  • Puberty

ASJC Scopus subject areas

  • Food Animals
  • Animal Science and Zoology
  • Endocrinology

Fingerprint Dive into the research topics of 'Maternal age influences the number of primordial follicles in the ovaries of yearling Angus heifers'. Together they form a unique fingerprint.

  • Cite this

    Tenley, S. C., Gomes, R. S., Rosasco, S. L., Northrop, E. J., Rich, J. J. J., McNeel, A. K., Summers, A. F., Miles, J. R., Chase, C. C., Lents, C. A., Perry, G. A., Wood, J. R., Cupp, A. S., & Cushman, R. A. (2019). Maternal age influences the number of primordial follicles in the ovaries of yearling Angus heifers. Animal Reproduction Science, 200, 105-112. https://doi.org/10.1016/j.anireprosci.2018.12.004