1. Got Babies? Embryo Transfer in Livestock
CLF3256
Kati Chamberlin - AgEd 410, Spring 2013

2. Introduction What is embryo transfer?
Removing fertilized eggs from a donor and placing them in a recipient female
Most common in beef and dairy cattle
Also known as “ova” transplantation

3. How does it work? 

4. What’s the process? Superovulation Insemination
Donor female is stimulated to ovulate more than one egg/cycle
Hormones are injected to cause superovulation
Insemination
The donor cow (the cow superovulated) is bred

5. Common hormones used for superovulation
PMSG (pregnant mare’s serum gonadotropin)
FSH (follicle stimulating hormone)
eCG (equine chorionic gonadotrophin)
Prostaglandin F2 alpha
LH (luteinizing hormone)

6. What’s the process? 3. Ova Collection (Flushing) Nonsurgical:
rubber catheter inserted through cervix
saline solution flushed into and out of uterus
harvests the embryos 7-8 days after estrus
30 minute or less procedure
standard method

7. Click HERE if video does not play
Flushing process
Click HERE if video does not play

8. What’s the process? 4. Evaluation of the Embryos
Regularity of shape of the embryo
Compactness of the blastomeres
Variation in cell size
Color and texture of the cytoplasm
Blastomeres: the dividing cells within the boundaries of the embryo
Cytoplasm: the fluid within the cell wall

9. What’s the process? 4. Evaluation of Embyo’s cont.
Overall diameter of the embryo
Presence of extruded cells and vesicles
Regularity of the zona pellucida
Zona pellucida: the protective layer of protein and polysaccharides around the single celled embryo
Vesicles: small bubble-like structures in the cytoplasm

10. Embryo Classification
Grades:
Grade 1: Excellent or Good
Grade 2: Fair
Grade 3: Poor
Grade 4: Dead or degenerating

11. Embryo Classification
Stage of Development:
Stage 1: Unfertilized
Stage 2: 2 to 12 cell
Stage 3: Early morula
Stage 4: Morula
Stage 5: Early Blastocyst
Stage 6: Blastocyst
Stage 7: Expanded Blastocyst
Stage 8: Hatched Blastocyst
Stage 9: Expanding Hatched Blastocyst

12. What’s the process? 5. Implantation
Recipient cows must be at right stage in estrous cycle to receive embryo
Recipient cows are synchronized with donor
The eggs are transferred to the recipient cows

13. Quick! What are the five processes of Embryo Transfer?

14. Benefits of Embryo Transfer
A dozen calves might be obtained from a valuable cow in one year
The rate of genetic improvement would quicken
Progeny testing of heifers can be done quicker
Genetically inferior animals could be made more productive by using them as recipient animals

15. Benefits of Embryo Transfer
Large numbers of fertilized eggs can be transferred from young heifers
Large amount of fertilized eggs can be transferred into mature recipients
Valuable cows that fail to conceive due to hormonal defects would not need to be culled

16. Limitations Expensive
The technique for harvesting the ova is complicated
Donors used repeatedly may become incapable of carrying to full term

17. FFA/SAE and Career opportunities
Bred replacement heifer for the fair
Embryologist
Internship with veterinarian
Veterinarian tech/ Veterinarian
In-vitro fertilization at a Dairy
Embryo transfer technician

18. Are there any limitations to using frozen embryos?
What do you think has better pregnancy rates, embryos transferred that were frozen or fresh?
Are there any limitations to using frozen embryos?