Today, nutraceuticals have been recognized as any natural product, food or dietary supplement that provides medical or health benefits including the prevention of diseases. Keeping these aspects in view, the book covers different types of Nutraceuticals used in livestock and poultry, their role, mode of application, advantages and disadvantages if any. In chapter 1, the concepts of feeding nutraceuticals have been discussed and classified into several groups. Chapter 2 presents feeding of antibiotics to poultry and livestock species and how it has been gradually replaced by different feed additives preferentially called as nutraceuticals. Chapter 3 to chapter 8 deals with different nutraceuticals often fed to poultry and livestock like probiotics, prebiotics, enzymes, organic acids, fatty acids and phytobiotics. The chapters introduce and classify the corresponding nutraceutical agents and then present a detail discussion on its efficacy as a feed ingredient, mode of action, specific rate of inclusion in the diet.