A new hormonal protocol supports early development of in vitro-produced embryos after transfer to anoestrus mares

Reprod Domest Anim. 2024 Oct:59 Suppl 3:e14622. doi: 10.1111/rda.14622.

Abstract

The present study aimed to evaluate whether primed anoestrus mares are suitable recipients for embryos produced by intracytoplasmic sperm injection (ICSI). Anoestrus was confirmed in four mares and daily doses of oestradiol benzoate (6 mg in total) over 5 days were administered; after 3 days of rest, oral altrenogest was administered at 0.088 mg/kg and embryos (1 to 5 embryos per mare; 15 in total) were transferred 3.5 days after progesterone onset. Uterine lavage was conducted 48 h after transfer. The results revealed an 80% embryo recovery rate, and among the retrieved embryos, 67% showed evident intrauterine development. Hence, ICSI-derived embryos can be successfully transferred to primed anoestrus mares, but more studies are required to ensure further embryo development and foaling.

Keywords: anoestrus recipient; in vitro embryo; mare; transfer.

MeSH terms

  • Anestrus* / drug effects
  • Animals
  • Embryo Transfer* / veterinary
  • Embryonic Development / drug effects
  • Estradiol* / administration & dosage
  • Estradiol* / analogs & derivatives
  • Estradiol* / pharmacology
  • Female
  • Horses / embryology
  • Pregnancy
  • Progesterone / pharmacology
  • Sperm Injections, Intracytoplasmic* / veterinary
  • Trenbolone Acetate* / administration & dosage
  • Trenbolone Acetate* / analogs & derivatives
  • Trenbolone Acetate* / pharmacology

Substances

  • Estradiol
  • estradiol 3-benzoate
  • Trenbolone Acetate
  • altrenogest
  • Progesterone