Effects of threonine on broilers: an in-depth review on growth, gut health, and immune function

This review examines the pivotal role of threonine (Thr), the third limiting essential amino acid, in optimizing broiler nutrition, particularly with corn–soybean meal-based diets, based on recent research highlights how different dietary levels of Thr influence key physiological parameters, including growth performance, intestinal health, immune function, and carcass composition. As poultry genetics and management practices advance, conventional Thr recommendations are being reassessed. Emerging evidence indicates that supplementing Thr beyond traditional levels (0.74–0.81%) can significantly enhance body weight gain, feed efficiency, gut integrity, immune competence, and meat yield. These improvements are largely attributed to the amino acid’s vital roles in supporting digestive and immune system functions. Current data suggest optimal Thr inclusion ranges of 0.67–0.90% for growth, 0.77–1.10% for gut health, 0.60–1.02% for immune response, and 0.62–0.97% for carcass traits. Collectively, these findings underscore the need for precision in amino acid formulation to meet the complex nutritional demands of modern broilers. The insights presented in this review provide a timely resource for nutritionists and researchers seeking to refine Thr supplementation strategies to achieve efficient and sustainable poultry production.