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Manipulating Ovulation and Estrous Synchronization

Manipulating Ovulation and Estrous Synchronization. John Parrish. Why Cycle Control?. Group females for parturition: Decrease labor, calving period More uniform weaning weights. Reduce or eliminate estrus detection. Needed for artificial insemination :. Reduce calving season.

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Manipulating Ovulation and Estrous Synchronization

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  1. Manipulating Ovulation andEstrous Synchronization John Parrish

  2. Why Cycle Control? • Group females for parturition: • Decrease labor, calving period • More uniform weaning weights. • Reduce or eliminate estrus detection. • Needed for artificial insemination: Reduce calving season

  3. Manipulating Ovulation • Hormonal induction of ovulation • PGF2a • GnRH • Progestins • Superovulation • FSH • eCG

  4. Cattle

  5. Principle of PGF2a Use • Regress active corpus luteum • Only effective on a day 5 - 17 CL • Not effective on days: • 1 - 4 (CL not responsive) • 18 - 21 (CL already regressed) • Represents 1/3 of estrous cycle

  6. Ovulation Estrous Cycle in the Bovine Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  7. Induction of Ovulation with PGF2a Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  8. PGF2 Induction of Ovulation with PGF2a Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  9. PGF2 Induction of Ovulation with PGF2a Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  10. PGF2 Induction of Ovulation with PGF2a Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  11. PGF2 Induction of Ovulation with PGF2a Progesterone Follicular Size • Works on CL • Ovulation time dependent on status of follicular wave 9 16 21 Ovulation Day After Ovulation

  12. Principle of GnRH Use • Luteinize or Ovulate a dominant follicle • Terminates the current follicular wave • Inhibin and Estradiol decrease • FSH increases to “recruit” a new follicular wave • No effect on old CL if present • A dominant follicle must be present • Generally followed by PGF2a to regress CL formed or old CL

  13. Principle of GnRH Use • Induce ovulation of a dominant follicle • Used for timed AI • No CL present • Dominant follicle must be present

  14. Timed AI 8 - 18 hours Ovsynch GnRH PGF2 GnRH 7 Days 36 - 48 hours Eliminate current follicular wave Luteolysis Ovulates dominant follicle Dairy - OK Beef - Problematic

  15. Ovulation Dominance Selection Recruitment Ovsynch Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  16. GnRH Ovsynch Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  17. GnRH Ovsynch Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  18. GnRH PGF2a Ovsynch Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  19. GnRH PGF2a GnRH AI Ovsynch Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  20. Timed AI 8 - 18 hours Ovsynch GnRH PGF2 GnRH 7 Days 36 - 48 hours Eliminate current follicular wave Luteolysis Ovulates dominant follicle

  21. Use of Progestogens • Principle • Provides progesterone • Simulates a CL • Prevents ovulation • Has no effect on the animal’s CL (ie. normal lifespan) • Does not regress the CL!!!! • Remove after animal’s CL regresses • Current or next follicular wave will ovulate!!!! • Occurs 2 – 5 days latter • May use PGF2a to regress animal’s CL • Administration • Injection, Feed (MGA), Implant, Control Internal Drug Release (CIDR)

  22. Normal Cycle Progesterone Follicular Size 9 16 21 Ovulation Day After Ovulation

  23. Normal Cycle Follicular Size CL Prog. Ovulation 9 16 21 26 Day After Ovulation

  24. CIDR CIDR Prog. Follicular Size CL Prog. Ovulation 9 16 21 26 Day After Ovulation

  25. Co-Synch + CIDR GnRH GnRH PGF2 AI CIDR 60 ± 6 hrs 0 7 10 Treatment Day

  26. Pre-synchronization • 2 – PGF2a injections 14 days apart • 2nd shot is 10 – 11 days before synchronization program • Presynch • Double ovsynch • Same as ovsynch • 2nd GnRH is 7 days before 1st ovsynch GnRH • PG-3-G • PGF2a , wait 3 days, GnRH, wait 7 days before synchronization program

  27. Superovulation

  28. Progestens Effect on Ovulation Ovulation Ovulation Progesterone From C.L. Estrus Estrus 0 17 21 Follicular Wave Follicular Wave Follicular Wave

  29. Stimulating Follicular Development eCGorFSH Multiple Ovulations Ovulation Estrus Estrus Progesterone From C.L. PGF2a 17 eCG orFSH Estrus Estrus Progesterone. First Follicular Wave 10-12

  30. Sheep • Progestin • CIDR • In season - works alone • Out of season - requires eCG • Prostaglandin • Only works in season • Lights - decrease day length • Melatonin - give orally or IM

  31. Swine • Prostaglandin • Not of practical • Only effect days 12 - 17 • Progestins - Altrenogest (Matrix) • MGA causes ovarian cysts • Regumate (oral) for 18 days • Cost is $5 - $10/day • Wean Piglets • Puberty Induction - PG600 (eCG + HCG)

  32. Equine • Prostaglandin • Mare CL more sensitive than cow’s • Only effective in season • HCG – ovulation induction, >35 mm follicle • Progestins • Altrenogest (Regumate) • Only effective in season • Reduce estrus behavior in competition animals • Light • 16 hrs day light for 60 - 90 days.

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