Oestrus cycle is seen in -

Options

A. Cows and sheep
B. Rats and deers
C. Dogs and tiger
D. AII

Answer

### Step-by-Step Solution:

1. **Understanding the Oestrus Cycle**:
- The oestrus cycle is a reproductive cycle found in many non-primate mammals. It is characterized by periods of heat (oestrus), during which females are receptive to mating.

2. **Identifying the Options**:
- The question provides four options:
- A) Cows and sheep
- B) Rats and deer
- C) Dogs and tigers
- D) Owls

3. **Analyzing Each Option**:
- **Option A: Cows and Sheep**: Both of these animals are known to have an oestrus cycle.
- **Option B: Rats and Deer**: Both species also exhibit an oestrus cycle.
- **Option C: Dogs and Tigers**: These animals are also non-primate mammals that experience an oestrus cycle.
- **Option D: Owls**: Owls are birds and do not have an oestrus cycle; instead, they have a different reproductive cycle.

4. **Conclusion**:
- Since options A, B, and C include animals that undergo the oestrus cycle, while option D (owls) does not, the correct answer to the question "Oestrus cycle is seen in" would be A, B, and C.

### Final Answer:
The oestrus cycle is seen in **cows, sheep, rats, deer, dogs, and tigers** (options A, B, and C).

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