Selenium (Se) is an essential dietary trace element participating in the regulation of various physiological functions in humans and farm animals through its incorporation into a range of selenoproteins. Low Se content in main feed ingredients is a common problem worldwide and dietary Se supplementation is a current practice in ruminant nutrition. Recent research clearly proved that sodium selenite, used for the last 50 years as a feed supplement, is not an optimal form of Se. However, use of organic selenium in dairy and beef diets can help meet Se requirement and maintain health/high immunocompetence, productive and reproductive performance.

The goal of this book is to provide up-to-date information about the roles of Se in ruminant nutrition and health. A special emphasis is given to the role of selenium as an essential part of the integrated antioxidant system. The concept of using organic Se in ruminant nutrition is described in detail with emphasis on selenomethionine as a storage form of Se in the body. Also, specific Se deficiency-related disorders in ruminants are described and the importance of Se in growth, development, immunity and reproduction is demonstrated. Molecular mechanisms of protective effects of Se under stressful conditions of commercial milk and meat production are characterized.

This book will be of practical importance to dairy and beef producers, to nutritionists and vets as well as for animal scientists, students of agricultural colleges and universities. It will also be of interest for researchers in areas related to environmental sciences, food sciences, physiology, etc.