Poultry and pig nutrition: challenges of the 21st century focuses on the important challenges animal production faces in the light of increasing global feed scarcity, climate change and improvements in animal welfare. Animal nutrition plays a critical role in providing answers to these 21st century challenges. Internationally leading authorities in nutrition and nutrition-related disciplines provide their views and solutions. New research areas are discussed and the current gaps in our knowledge are identified. Among the topics discussed are the use of microbes for natural solutions, the importance of individual feed intake determination, technological treatments of feed ingredients, and advances in modelling. In addition, authors provide their insights on the effects of environment/housing on animal functioning and the impact of climate change on the mycotoxin content of feed ingredients as well as the importance of pro- and antioxidant balance in animals. The increasing global demand for feed will increase the search for alternative feed ingredients especially new protein sources while for an environmentally sustainable human diet, life cycle assessment needs to be combined with other modelling techniques that address environmental impacts of dietary choices at the (inter)national level. Future challenges require new solutions and innovations, and this book contains a collection of ideas for our 21st century challenges.