University:
Sam Houston State University
Course:
BIOL 1406 | General Biology I
Academic year:

2024
Views:

79

Pages:

10
Author:

5CelestialChronicle

Embryo Size and Quality  Embryos are microscopic in size (about 0.2 mm).  Only undamaged embryos at proper maturity should be transferred. Embryo Quality The embryos on the left are damaged and should not be transferred. The embryo on the right is of proper maturity and quality and should be transferred. Transferring the Embryos  The embryo to be transferred is put into a small, plastic straw and then loaded into an embryo transfer gun. Transferring the Embryos (continued)   The embryo is then inserted into either the left or right uterine horn depending on which ovary has a corpus lutuem (CL). The CL is a structure on the ovary that secretes the hormone progesterone which is needed to maintain the pregnancy. Transfer Immediately or Freeze  Embryos should be transferred as soon as possible after the flush (within 8 hours at least).  Embryos can also be frozen for later implantation and stored in liquid nitrogen tanks. Benefits to Embryo Transfer -A single heifer or cow is able to produce multiple calves from the same genetic line. -An older superior cow is able to donate ovules for embryo transfer. -Embryos can be frozen and stored for future use. FACTS -In 1987, 3.6% (5,105) of all calves registered were a result of embryo transfer. -In 2002, 25,093 calves resulting from ET were registered. This was 8.9% of all calves registered. -In 2007, just under 40,000 calves resulting from ET were registered. This accounted for about 11.5% of total registrations. Disadvantages of ET -Increased expenses and higher breakeven costs for calves. • Requires a higher level of management. • Increased potential for spread of certain diseases. • Not all potential donors respond positively to treatment. Summary  ET can be costly, so the return on the investment should always be greater than the input costs.  ET should only be performed using donor cows of superior genetics.  Bull selection should be based on superior genetics as well. Conclusion  If the required conditions are met, embryo transfer can be a beneficial way to produce superior cattle.