The Germ Theory of Disease, proposed by Louis Pasteur, states that many diseases are caused by microorganisms such as bacteria, viruses, and fungi. This theory is crucial in understanding and preventing infectious diseases in animals and humans.


The One Health Concept emphasizes the interconnectedness of human, animal, and environmental health. It recognizes that the health of animals, humans, and the environment are closely linked, and the prevention and control of diseases require a multidisciplinary approach.


Animal Welfare Science focuses on the well-being and quality of life of animals. It involves understanding their behavior, physiology, and needs, and developing ethical and sustainable practices in animal husbandry and veterinary care.


Ethology is the study of animal behavior, and it plays a crucial role in animal husbandry and veterinary science. Understanding animal behavior helps in designing appropriate housing, handling, and management practices that promote animal welfare and productivity.


Vaccination is a fundamental practice in veterinary medicine to prevent the occurrence and spread of infectious diseases. The theory behind vaccination is based on the principle of stimulating the immune system with a harmless form of the disease-causing agent to develop immunity.


Understanding the nutritional requirements of animals and developing balanced feed formulations is essential for their health and productivity. This field of study involves the analysis of different feed ingredients, their nutritional composition, and their impact on animal health and performance.


Epidemiology is the study of the occurrence, distribution, and determinants of diseases in populations. It helps in identifying risk factors, understanding disease patterns, and designing effective control measures. Epidemiological studies are crucial for disease surveillance and control in animal populations.


Reproductive physiology is the study of the reproductive processes and functions in animals. It includes understanding the reproductive cycle, breeding techniques, fertility management, and assisted reproductive technologies. This knowledge is vital for efficient breeding and reproduction in animal husbandry.


Pharmacology and therapeutics involve the study of drugs and their effects on animals. It includes understanding drug interactions, dosage regimens, and treatment protocols for various diseases and conditions. This field helps veterinarians in providing effective medical care to animals.

These scientific theories and models form the foundation of Animal Husbandry and Veterinary Science. Familiarity with these concepts will be beneficial for the UPSC exam and for a career in the field of animal husbandry and veterinary sciences.