Biotechnology as any technique that used living organisms to make or modify a product, to improve plants or animals or to develop microorganisms for specific uses. Biotechnology as any technique that used living organisms to make or modify a product, to improve plants or animals or to develop microorganisms for specific uses. Animal biotechnology in use today is based on the science of genetic engineering. Under the umbrella of genetic engineering exist other technologies, such as transgenics and cloning, that also are used in animal biotechnology. Immunology is the study of the immune system and is a very important branch of the medical and biological sciences. The immune system protects us from infection through various lines of defence. If the immune system is not functioning as it should, it can result in disease, such as autoimmunity, allergy and cancer. Immunity is a biological term that describes a state of having sufficient biological defences to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components. The non-specific components act either as barriers or as eliminators of wide range of pathogens irrespective of antigenic specificity. Other components of the immune system adapt themselves to each new disease encountered and are able to generate pathogen-specific immunity. This book sums up information about Animal Biotechnology and is a valuable tool for students as well as teachers. The aim of this book is to provide the readers materials on the subject in a lucid and readable form so as to enable the research scholars, scientists, zoologist and even the common men to understand the subject properly.