Many attempts to improve livestock in the tropics have been made by 'upgrading ' through crossbreeding them with temperate breeds. The major problems faced during the failed cattle breeding are

Options

A. the breeding programmes have been too complicated in term of logistics, technology and requirements of resources without considering the infrastructure available.
B. indiscriminate crossbreeding of indigenous breeds with exotic breeds without enough consideration of environment conditions for production.
C. lack of analysis of the different socio-economic and culture roles that liverstock play in each situation, usually leading to wrong breeding objectives and neglect of the potential of various indigenous breeds of livestock.
D. All of these

Explanation

### Step-by-Step Solution:

1. **Understanding the Context**:
- The question discusses the attempts to improve livestock in tropical regions through crossbreeding with temperate breeds.
- It highlights that these attempts have often failed, and we need to identify the major problems faced during these breeding efforts.

2. **Identifying the Differences**:
- Livestock in tropical regions generally have lower productivity compared to those in temperate regions.
- Factors contributing to this difference include climatic conditions and genetic traits.

3. **Challenges in Crossbreeding**:
- Crossbreeding tropical breeds with temperate breeds has not been successful due to several reasons:
- **Logistical Complications**: Breeding programs may be complicated in terms of logistics, technology, and resource requirements. If the necessary infrastructure is not in place, the breeding efforts are likely to fail.
- **Indiscriminate Crossbreeding**: Many attempts have been made without considering the specific environmental conditions that affect production. This indiscriminate approach can lead to poor outcomes.
- **Socio-Economic Factors**: There is often a lack of analysis regarding the socio-economic and cultural roles that livestock play in different regions. This oversight can lead to incorrect breeding objectives and strategies.

4. **Conclusion**:
- All the mentioned factors contribute to the failure of cattle breeding programs in tropical regions. Therefore, the correct answer to the question is that all of these factors are major problems faced during the failed cattle breeding attempts.

### Final Answer:
The major problems faced during the failed cattle breeding in tropical regions include:
- Complicated breeding programs without adequate infrastructure.
- Indiscriminate crossbreeding without considering environmental conditions.
- Lack of analysis of socio-economic and cultural roles of livestock.

Thus, the correct answer is **Option D: All of these**.

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