pThis collection features five peer-reviewed reviews on dietary supplements in poultry nutrition. ppbrppThe first chapter reviews the current status of research on feed enzymes with an emphasis on identifying the key challenges researchers face in terms of current trends in enzyme development, mechanisms of action and enzyme efficacy. ppbrppThe second chapter considers the role of probiotics in optimising gut function in poultry. It reviews the development of novel, cost-effective, feed-stable, direct-fed microbials with potential for widespread utilization and improved production. ppbrppThe third chapter discusses the role of essential oils and botanicals in improving gut function in poultry, focussing on four major functions of phytobiotics that could potentially contribute to gut health digestive conditioning, antimicrobial property, immunomodulation and gut microbiota modulation. ppbrppThe fourth chapter considers the development of alternative protein sources for poultry nutrition