Seventy years of progestagen treatments for management of the sheep oestrous cycle: where we are and where we should go

Reprod Fertil Dev. 2020 Mar;32(5):441-452. doi: 10.1071/RD18477.

Abstract

Management of the ovine oestrous cycle is mainly based on the use of exogenous hormones to mimic or enhance (progesterone and its analogues) or manipulate (prostaglandin F2α and its analogues) the activity of the corpus luteum, combined with the application of other hormones mimicking the pituitary secretion of gonadotrophins (e.g. equine chorionic gonadotrophin). These protocols have been applied without major change for decades but, now, there are two reasons to reconsider them: (1) our greatly improved knowledge of the dynamics of ovarian physiology, following the application of transrectal ultrasonography, indicates that modification of the protocols may improve fertility yields and (2) increasing concerns about animal health and welfare, food safety and the environmental impact of the treatments, as evidenced by public opinion and therefore market forces. Here, we offer an overview of these issues, introduce an updated protocol and suggest ways for future improvements to the protocols.

Publication types

  • Historical Article
  • Review

MeSH terms

  • Animals
  • Estrous Cycle / drug effects*
  • Estrus Synchronization / drug effects
  • Female
  • Fertility Agents, Female / administration & dosage*
  • Fertility Agents, Female / adverse effects
  • History, 20th Century
  • History, 21st Century
  • Insemination, Artificial / adverse effects
  • Insemination, Artificial / history
  • Insemination, Artificial / veterinary*
  • Ovary / drug effects*
  • Ovary / physiology
  • Ovulation Induction / adverse effects
  • Ovulation Induction / history
  • Ovulation Induction / veterinary*
  • Pregnancy
  • Progestins / administration & dosage*
  • Progestins / toxicity
  • Sheep / physiology*

Substances

  • Fertility Agents, Female
  • Progestins