Abstract
Phytogenic feed additives have undergone extensive testing in swine production to determine their effects on gastrointestinal function and health, as well as their implications for pigs' systemic health and welfare, flock production efficiency, food safety, and environmental impact. These feed additives derived from plants, encompassing herbs, spices, fruits, and various plant components, contain numerous bioactive ingredients. An examination of published documents concerning the supplementation of phytogenic feed additives uncovers conflicting findings about their efficacy in swine production. This suggests that additional effort is required to ascertain the suitable inclusion levels and thoroughly clarify their mechanisms of action. This review aims to summarise the prevailing trends in the application of phytogenic feed additives in poultry, emphasising their effects on growth performance, nutrient digestibility, biochemical profiles, gene expression, hypocholesterolemic properties, immunity, meat quality, fatty acid composition, amino acid content, and the gut microbiota of swine.