**Preface**

As global consumer demand for poultry meat and eggs continues to rise, it is necessary to improve diet precision and utilisation among birds to keep the costs of poultry products low and reduce the industry's environmental impact. One possible approach is to feed cheaper, more readily available, and less environmentally harmful feed ingredients. However, these alternative ingredients are often rich in anti-nutritional factors, negatively impacting bird health and productivity. This Special Issue explores the potential of various alternative ingredients for poultry diets and identifies approaches to overcoming barriers to their adoption. The digestibility of common feed ingredients, such as corn and wheat, can also be enhanced, reducing the wastage of valuable nutrients. This can be achieved by applying feed additives, such as enzymes, and improving the accuracy of feed formulations. This Special Issue features 27 articles to provide insight into the inter-relations between nutrition, metabolism, gut microflora, poultry performance, production, and product quality. The impact of diet on several different parameters has been examined, including bird performance in terms of bird growth, chick health, and meat and egg quality, as well as immunity, gut morphology and gene expression, bone characteristics, blood and neuron health, and microbiota composition, thus presenting a holistic and dynamic overview of current research in this field.

> **Natalie Morgan and Youssef A. Attia** *Editors*
