Progesterone Releasing Intravaginal Device
Encyclopedia
Intravaginal progesterone devices are broadly used in the control of reproductive management in cattle. The chain-mechanism of action is as follows:
  1. Progesterone suppresses the release of GnRH
    Gonadotropin-releasing hormone
    Gonadotropin-releasing hormone , also known as Luteinizing-hormone-releasing hormone and luliberin, is a tropic peptide hormone responsible for the release of follicle-stimulating hormone and luteinizing hormone from the anterior pituitary. GnRH is synthesized and released from neurons within...

    .
  2. Low levels of GnRH prevent the emergence of a dominant follicle by diminishing release of LH
    LH
    LH, Lh, or lh may stand for:*Laurel and Hardy*Leasehold *Left-handed or left hand*Letterhead, the heading at the top of a sheet of letter paper*lh, a digraph for many languages...

     and FSH
    FSH
    FSH may refer to:* Follicle-stimulating hormone* Fox Sports Houston, a regional Fox Sports Net affiliate station for the Houston, Texas area* Facioscapulohumeral muscular dystrophy* International Civil Aviation Organisation code for Flash Airlines...

     hormones. Current follicular waves cease and a new wave emerges 3–5 days after implant.
  3. A dominant follicle develops but there is no ovulation as LH release is prevented by suppression of GnRH.
  4. Removal of progesterone device produces a surge of GnRH, generating a pulse of LH that induces ovulation.

Clinical uses of PRID

  1. Synchronisation of oestrus in conjunction with prostaglandin. The PGF2α injection helps to ensure there is no residual CL and the potentially ovulating follicle has been held primed for less time, enhancing its viability.


Protocol - PRID for 9 days. PGF2α injection on days 5-8. Serve on observed oestrus or fixed time once at 56h or twice at 48h and 72h.
  1. Induction of oestrus in anoestrus cows
  2. Treatment of follicular cysts
  3. Persistent ovarian follicles
  4. Improve oocyte quality
  5. Reduction of early embryonic death and improved fertility
  6. Treatment of repeat breeders
  7. Increased fertility in embryo transfer
    Embryo transfer
    Embryo transfer refers to a step in the process of assisted reproduction in which embryos are placed into the uterus of a female with the intent to establish a pregnancy...

    protocols
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