Combined Effects of Spirulina (<i>Limnospira platensis</i>) Dietary Inclusion and Heat Stress on the Hepatic and Muscle Metabolomes of Two Strains of Slow-Growth Broilers

Heat stress (HS) affects poultry growth, immunity, and meat quality. Slow-growing strains may respond differently due to lower metabolic demands. This study assessed the impact of 15% Spirulina (SP; Limnospira platensis) dietary inclusion on the hepatic and muscle metabolomes of two slow-growing broiler strains under HS using proton nuclear magnetic resonance spectroscopy. Forty male broilers were allocated into four groups: fully feathered + control diet (FFC), fully feathered + 15% SP diet (FFSP), naked neck + control diet (NNC), and naked neck + 15% SP diet (NNSP), and exposed to 30 °C for 84 days. Liver metabolomic analysis revealed no clear separation in principal component analysis, but partial least-squares showed metabolic differences, particularly between FFC and FFSP. Breast muscle analysis showed a metabolic overlap. Spirulina dietary inclusion influenced hepatic metabolism, with minor strain differences under HS. Further studies are needed to clarify its role in HS management.