Enhancing embryo numbers for transplantation The success of embryo transfer depends on obtaining many embryos from elite animals. Which intervention is specifically used to achieve this?
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AExogenous gonadotrophic hormones (superovulation)
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BEndogenous gonadotrophic pulses only
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CBoth exogenous and endogenous hormones without timing control
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DFSH (Follicle Stimulating Hormone) for superovulation protocols
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EFeeding high-energy diets only
Answer
Correct Answer: FSH (Follicle Stimulating Hormone) for superovulation protocols
Explanation
Introduction / Context:Embryo transfer programs rely on superovulation to collect multiple embryos per cycle from genetically superior donors. The hormonal choice and regimen directly influence embryo yield and quality.
Given Data / Assumptions:
- Goal is increased ovulation rate in the donor female.
- Veterinary reproductive management and synchronization are available.
Concept / Approach:FSH is the standard pituitary-derived (or recombinant) hormone administered in decreasing doses over several days to recruit and mature multiple follicles, markedly increasing ovulation numbers relative to natural cycles.
Step-by-Step Solution:
Select an exogenous hormone: FSH is preferred for multi-follicular recruitment.Administer according to a superovulation protocol aligned with estrous synchronization.Breed and recover embryos by uterine flushing on the appropriate day.Verification / Alternative check:Controlled studies show FSH regimens yield more transferable embryos than reliance on endogenous hormones alone.
Why Other Options Are Wrong:
- Exogenous gonadotrophins (generic) are conceptually correct, but the specific, widely used agent is FSH; option (d) names it precisely.
- Endogenous pulses: insufficient for superovulatory responses.
- “Both without timing control”: timing is essential; lack of control reduces success.
- Diet alone cannot induce superovulation.
Common Pitfalls:Incorrect dosing schedules, poor synchronization, and ignoring donor variability (breed, parity) can lower embryo yields.
Final Answer:FSH (Follicle Stimulating Hormone) for superovulation protocols