Got Babies?Embryo Transfer in
LivestockCLF3256
Kati Chamberlin - AgEd 410, Spring 2013
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
How does it work?

http://www.oces.okstate.edu/extension-fact-sheets-2/mobile-fact-sheets/ansi-3158/ANSI-3994%20Figure%201.jpg/image_preview
What’s the process?
1. SuperovulationDonor female is stimulated to ovulate more
than one egg/cycle
Hormones are injected to cause superovulation
2. InseminationThe donor cow (the cow superovulated) is
bred
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)
http://www.nzdl.org/gsdl/collect/fnl2.2/archives/HASH42a2.dir/p16.gif
What’s the process?3. Ova Collection (Flushing)
Nonsurgical: rubber catheter inserted through cervix saline solution flushed into and out of uterusharvests the embryos 7-8 days after estrus30 minute or less procedurestandard method
http://www.fao.org/docrep/004/T0117E/T0117E10.jpg
What’s the process?
4. Evaluation of the EmbryosRegularity of shape of the embryoCompactness of the blastomeres Variation in cell sizeColor and texture of the cytoplasm
What’s the process?
4. Evaluation of Embyo’s cont.Overall diameter of the embryoPresence of extruded cells and vesiclesRegularity of the zona pellucida
Embryo Classification
Grades: Grade 1: Excellent or Good Grade 2: Fair Grade 3: Poor Grade 4: Dead or degenerating
Embryo ClassificationStage of Development:
Stage 1: Unfertilized Stage 2: 2 to 12 cellStage 3: Early morulaStage 4: MorulaStage 5: Early BlastocystStage 6: BlastocystStage 7: Expanded BlastocystStage 8: Hatched BlastocystStage 9: Expanding Hatched Blastocyst
http://www.oces.okstate.edu/extension-fact-sheets-2/mobile-fact-sheets/ansi-3158
What’s the process?
5. ImplantationRecipient 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
Quick! What are the
five processes of Embryo Transfer?
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
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
Limitations
Expensive
The technique for harvesting the ova is complicated
Donors used repeatedly may become incapable of carrying to full term
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
What do you think has better pregnancy rates, embryos
transferred that were frozen or fresh?
Are there any limitations to using frozen embryos?