Studying Animal Husbandry and Veterinary Science as an optional subject for UPSC exams opens up a range of career prospects in various fields related to animal health, welfare, and management. Here are the details:

1. Government Services:
- Veterinary Officer: Graduates can join government veterinary services as veterinary officers. They are responsible for ensuring animal health, disease control, and implementing animal welfare policies.
- Animal Husbandry Officer: Graduates can work as animal husbandry officers, responsible for promoting livestock production, breeding programs, and providing technical support to farmers.
- Research Officer: Opportunities exist in government research institutions where graduates can work as research officers, conducting studies and experiments to improve animal health, nutrition, and breeding techniques.
- Regulatory Bodies: Graduates can also work in regulatory bodies such as the Animal Welfare Board, Food Safety and Standards Authority, or Pollution Control Board, ensuring compliance with animal welfare and environmental regulations.

2. Public Sector Undertakings:
- Graduates can work in public sector undertakings like the Food Corporation of India, National Dairy Development Board, and various state-level milk cooperatives, where they can contribute to the management and development of the livestock sector.

3. Defense Services:
- Animal Husbandry Officers: In the defense services, graduates can join as animal husbandry officers, responsible for managing and maintaining the health and well-being of the animals used in various operations.

4. Research and Academia:
- Graduates can pursue research careers in animal health, genetics, nutrition, and other related fields. They can work in research institutions, universities, and agricultural colleges as research scientists or lecturers.
- Veterinary Pathologists: There is a demand for veterinary pathologists who diagnose and investigate animal diseases. Graduates can work in diagnostic laboratories or veterinary pathology departments in research institutes.

5. Entrepreneurship:
- Graduates can set up their own veterinary clinics, animal farms, or start animal-related businesses such as pet grooming and boarding services, animal feed manufacturing, or veterinary pharmaceuticals.

6. International Organizations:
- Graduates can work with international organizations like the World Health Organization (WHO), Food and Agriculture Organization (FAO), or the World Organization for Animal Health (OIE) in positions related to animal health, disease control, or food safety.

Overall, studying Animal Husbandry and Veterinary Science as an optional subject for UPSC exams provides a diverse range of career prospects in government services, research, academia, entrepreneurship, and international organizations, enabling individuals to contribute to animal welfare, healthcare, and sustainable livestock production.