Oestrus synchronisation and superovulation alter the production and biochemical constituents of ovine cervicovaginal mucus

Anim Reprod Sci. 2016 Sep:172:114-22. doi: 10.1016/j.anireprosci.2016.07.008. Epub 2016 Jul 22.

Abstract

Controlled breeding programmes utilising exogenous hormones are common in the Australian sheep industry, however the effects of such programmes on cervicovaginal mucus properties are lacking. As such, the aim of this study was to investigate cervicovaginal (CV) mucus from naturally cycling (NAT), progesterone synchronised (P4), prostaglandin synchronised (PGF2α), and superovulated (SOV) Merino ewes. Experiment 1; volume, colour, spinnbarkeit, chemical profile and protein concentration of mucus (NAT, P4, PGF2α and SOV; n=5 ewes/treatment) during the follicular (5 d) and luteal phases (8 d) was investigated. Experiment 2; in vivo mucus pH and in vitro mucus penetration by frozen-thawed spermatozoa (NAT, P4 and SOV; n=11 ewes/treatment) was investigated over oestrus (2 d) and the mid-luteal phase (pH only, 2 d). Oestrus mucus was more abundant, clearer in colour and less proteinaceous than luteal phase mucus (p<0.05). SOV increased mucus production and protein concentration (p<0.05) while PGF2α reduced mucus volume (p<0.05). Mucus pH (oestrus 6.2-6.5), chemical profile and mucus penetration by sperm were unchanged (p>0.05). Results indicate that exogenous hormones used for controlled breeding affect cervicovaginal mucus production, but few other tested characteristics. Further research is required to explain fertility differences between synchronised and naturally cycling animals following cervical AI.

Keywords: Cervicovaginal; Hormone; Oestrogen; Oestrus; Progesterone; Prostaglandin.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Animals
  • Cervix Mucus / chemistry
  • Cervix Mucus / physiology*
  • Chorionic Gonadotropin / administration & dosage
  • Chorionic Gonadotropin / pharmacology
  • Dinoprost / administration & dosage
  • Dinoprost / pharmacology
  • Estrus Synchronization*
  • Female
  • Follicle Stimulating Hormone / administration & dosage
  • Follicle Stimulating Hormone / pharmacology
  • Hydrogen-Ion Concentration
  • Progesterone / pharmacology*
  • Proteins / chemistry
  • Proteins / genetics
  • Proteins / metabolism
  • Sheep / physiology*
  • Superovulation / drug effects*

Substances

  • Chorionic Gonadotropin
  • Proteins
  • Progesterone
  • Follicle Stimulating Hormone
  • Dinoprost