1. Embryo Transfer
in Beef Cattle
Ms. Bailes
AGSC 336 – Advanced Animal Science

3. Objectives
• Define embryo transfer
• Explain the steps of embryo transfer
• List the advantages of embryo transfer
• List the disadvantages of embryo transfer

4. What is Embryo
Transfer?
Collecting embryos from a
superovulated donor cow...
…and transferring the embryos
to synchronized recipients to
complete the gestation period.

5. The Donor Cow
• Top quality female, free of
reproductive abnormalities
or genetic defects, proven
maternal qualities.
• Personal goals/preferences
play large part in donor
selection.
• Marketability of the donors
calves.

6. Superovulation of Donor
Day 0 to Day 4
• Follicle Stimulating Hormones
(Known as FSH)
• Injections 2x daily, 4 days
(Day 0 starts 8-14 days following estrus cycle.)

7. Superovulation--Day 3
Result: Multiple Folicles
• Prostaglandin injection
causing Corpus Luteum
regression to bring on
estrus.
Result: Multiple Folicles

8. Superovulation--Day 5
• Onset of estrus

9. A.I. of Superovulated Donor
• Artificially Inseminate when in
standing estrus, usually 5 days
after superovulation.
• Usually multiple inseminations at
12, 24, 36 hrs. after onset of
estrus.
• Preferably, more than one straw
of high quality semen.

10. Embryo Recovery from Donor
• Approximately 7 days after
breeding.
• Easy, takes less than 30
minutes.
• Insert foley catheter with
inflatable balloon into
donor’s uterus.
• Flushing solution (saline)
is introduced into each
uterine horn.

11. Recovery of Embryos
• Solution filled
uterine horn is
gently massaged.
• Fluid containing
the embryos is
drawn back out
and collected
though a filter into
a holding cylinder.

12. Embryo Processing
• After 20-30 minutes embryos
located with stereoscopic
microscope.
• Embryos are washed and
transferred to holding medium.
(Procedure generally repeated 3 times.)
• Embryos are evaluated for state
of development and quality.
• Initially classified: “good” or
“bad.” “Good” embryos are
further classified.

13. The Recipient
• Reproductively sound, good mothering ability.
• Good overall health, nutrition.
• Must be synchronized to receive the embryo.

14. Synchronization Protocol--Day 0
• Insert
intravaginal
CIDR.
• Administer 2 cc
combo Estradiol
Benzoate and
Progesterone.

15. Day 7
• Remove CIDR
• Administer 5cc
Prostaglandin

16. Day 8
• Final Injection:
1 cc Estradiol Benzoate

17. Day 8 through Day 10
• Day 8 pm
through Day
10am:
Observe for
onset of estrus.

18. Day 16--Transfer Embryo
• Transfer Embryo into
synchronized recipient
who has come into
estrus.
• Procedure is simple,
much like A.I.

19. Activity
• Each card has a step in the embryo transfer
process.
• Put yourselves in the proper order of
embryo transfer and then explain the
process.

20. Advantages of E.T.
• Increased number of calves of genetically
superior cows.
• Increased marketing opportunities--
offspring AND embryos.
• Ease of Import/Export.
• Embyros can be stored indefinitely.

21. Disadvantages of E.T.
• Increased expenses and higher break-even costs for
calves.
• Estrus detection required.
• Synchronization of recipient with donor.
• Specialized equipment and trained personnel.
• More expensive and time consuming than
traditional reproductive methods.

22. In Summary…
• E.T. is not for every herd.
• Each female born has thousands of potential
eggs.
• Complete the crossword puzzle which is a
summary/review of what we learned today.