Due to the ban of the antibiotic growth promoters new functional compounds will be characterized and their mode of action and efficacy of nutrient and tissue metabolism will be described. Safety and legal aspects in the production and the use feed additives and bioactive compounds will be presented. The book covers wide area of knowledge of dietary modulation of the gastrointestinal function in young animals through different kinds of feed additives: probiotics, prebiotics, organic acids, novel sources of feed enzymes, bioactive components and metabolic modifiers. The role of nutrition in relation to immune response and animal health, the problem of antinutrients in animal nutrition as well as biotechnological and ecophysiological aspects of nutrition will also be discussed. The book provides a comprehensive review and future perspectives in the modern nutrition of the growing animals. Critical review and state-of-the art articles written by recognized specialsists in animal nutrition and gastrointestinal physiology Novel approaches for improving gastrointestinal function in young farm animals New ways of interpretation of basic knowledge of nutrition