In livestock breeding experiments, which of the following stages is transferred to surrogate mothers?

Options

A. Unfertilised eggs
B. Fertilised eggs
C. 8 to 32 celled embryo
D. Frozen semen

Answer

To answer the question "In livestock breeding experiments, which of the following stages is transferred to surrogate mothers?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**: The question pertains to livestock breeding experiments, specifically focusing on the stages of embryos that are transferred to surrogate mothers.

2. **Identify Key Terms**: The options provided are:
- Unfertilized eggs
- Fertilized eggs
- A232 celled embryo
- Frozen semen

3. **Review the Process of Livestock Breeding**: In livestock breeding, particularly in techniques like Multiple Ovulation Embryo Transfer (MOET), the process involves:
- Administering hormones (like FSH) to induce multiple ovulation in female cattle.
- Collecting fertilized eggs after artificial insemination.

4. **Determine the Correct Stage for Transfer**:
- **Unfertilized Eggs**: These cannot be transferred as they have not developed into embryos yet.
- **Fertilized Eggs**: These are the initial stage post-fertilization but are not the stage transferred.
- **A232 Celled Embryo**: This is the correct stage, as it refers to embryos that have developed to a specific cell stage (8 to 32 cells) and are ready for transfer.
- **Frozen Semen**: This is used for insemination, not for transfer to a surrogate.

5. **Conclude the Answer**: Based on the above analysis, the correct answer is **A232 celled embryo**.

### Final Answer:
The stage transferred to surrogate mothers in livestock breeding experiments is **A232 celled embryo**.

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