This book provides a comprehensive examination of animal biotechnology and its practical applications in the fields of veterinary medicine, pharmaceuticals, and animal food production. Transgenic technologies are widely utilized in enhancing milk production and meat yield in farm animals, as well as in developing models for human diseases. Transgenic animals also play a crucial role in the production of proteins for human medical use. In addition, biotechnology facilitates xenotransplantation from animals to humans, and genetic engineering is commonly employed in farm animals. Nuclear transfer technology has emerged as a preferred method for cloning animals. The potential applications of biotechnology in managing animal diseases such as foot-and-mouth disease, classical swine fever, avian flu, and bovine spongiform encephalopathy are significant. Vaccines, particularly genetically engineered or DNA vaccines, are among the most important biotechnology-based products. Gene therapy for diseases in pet animals is a rapidly evolving field, as many of the technologies utilized in human clinical trials were initially developed in animals, and many of the diseases affecting cats and dogs are similar to those in humans. RNA interference technology is increasingly being employed in veterinary research. Molecular diagnosis, including polymerase chain reaction and its modifications, fluorescent in situ hybridization, and enzyme-linked immunosorbent assays, is playing an important role in veterinary practice. Newer biochip-based technologies and biosensors are also being utilized in veterinary diagnostics. This book aims to elucidate the complexities of biotechnology as they pertain to animal health and production.