Equine embryo transfer and other techniques
Dr Jose LenDiplomate American College of Theriogenology
Hahndorf, South AustraliaJune 4, 2016
Applications
• Increased numbers of foals from selected mares • Foals from mares that are in training or competition • Foals from mares that are unable to foal because of reproductive or non‐reproductive problems
• Investigation of embryo‐maternal interactions
www.laestrella.com.pa
Recipient mares selection
• 2 – 3 per donor mare • Age: 3 – 12 years• Sound mare
• Free of disease• Free of musculoskeletal problems• Reproductively sound
• Breeding soundness examination• Good cervical and uterine tone
• Easy to handle
• Hire a recipient mare
Mare synchronization
• Donor synchronized with recipients
• Synchronization protocols• Prostaglandins (two injections 14 days apart)• Progesterone + estrogen
Donor OV
0
Recipient OV
+4 +8‐1
Breeding management
• Donor and recipients• Uterine oedema• Follicular development
• ≥ 35 mm• Inseminate donor
• Fresh• Fresh cooled• Frozen
• Induce ovulation in all mares
Breeding management
• Post‐breeding• Donor
• Fluid?• Treat
• Recipients• Fluid?• Consider removing• Ovulation• Cervical tone• Uterine tone
Embryo flush
• 7 – 9 days after donor mare ovulates• Embryo recovery: 50%
www.foxvalleyequine.com
Embryo transfer
• Non‐surgical• Fresh• Fresh cooled for 24 h
• Good quality embryos• 70 – 75% pregnancy at day 15• 65% pregnancy at day 50
Recipient management post embryo transfer
• Progesterone supplementation• Controversial immediately post‐transfer• Indicated if signs of low progesterone in subsequent examinations
• Antibiotics• May be indicated until first examination post‐transfer
• Examinations• Day 11 post‐OV (donor)• Day 15• Day 20• Day 25• Day 35
Donor mare management post‐flush
• Prostaglandin after flush• Re‐examine mare the day after flush
• If fluid present• Uterine lavage
• Re‐examine few days later• If fluid still present
• Endometritis??
Other assisted reproductive teachnique(ART’s)• Deep horn insemination
• Insemination of low number of sperm
Why low dose insemination?
• Drastically reduce the insemination dose• Sex sorted semen• Improve fertility of frozen semen• Improve fertility of subfertile stallions
Comparison of low dose insemination
Hysteroscopic‐guidedDose
• 0.001 – 10 x 106 PMS Volume
• 20 – 500 μL Pregnancy rates
• 10 to 75% Cost $$$$
Ultrasound‐guided Dose
• 5 ‐ 25 x 106 PMS Volume
• 200 ‐ 1000 μL Pregnancy rates
• 0 to 50% Cost $
Morris LHA, Allen WR. An overview of low dose insemination in the mare. Reprod Dom Anim, 2002;37:206‐210.
Other assisted reproductive techniques (ART’s)• Oocyte transfer
• Infertile mares after breeding and/or embryo transfer• Damage to oviducts and endometrium• Ovulatory failure
• Oocyte from donor mare recovered• Transvaginal ultrasound guided aspiration
www.weatherfordequine.com
Other ART’s
• Oocyte transfer• Oocyte transfer into recipient mare • Recipient mare inseminated before transfer• Pregnancy rates
• Old mares: 30 – 40%• Young mares: 50 – 80% (Carnevale et al., 2004)
• Gamete intrafallopian transfer (GIFT)• Same as oocyte transfer• Small number of sperm inseminated into oviduct• Pregnancy rate: 27 – 82% (Carnevale et al., 2004)
Other ART’s
• Intracytoplasmic sperm injection (ICSI)• Production of multiple embryos from a mare• Salvage of mares genetic in case of sudden death• Sub‐fertile and infertile stallionsPre‐ovulatory or immature oocyte In vitromaturation
Other ART’s
• ICSI• Injection with one sperm• Culture for 7 – 8 days• Embryo transfer into recipient mare
• Embryos per collection: 0.4 – 1.3• Pregnancy: 60 – 65%
