Comparative evaluation of native slow-growing roosters: focus on gut integrity and physiological traits

Native poultry breeds are fundamental for sustainable farming, especially in agroecological systems emphasizing adaptability, resilience and product quality. However, data on their physiological and intestinal health profiles are limited. This study examines three Italian slow-growing chicken breeds: Bionda Piemontese, Bianca di Saluzzo and Millefiori Piemontese, reared under identical agroecological, free-range conditions. Parameters assessed include productive performance, blood traits, feather corticosterone, intestinal histomorphology and histopathology, nutrient digestibility, and caecal microbiota and volatile fatty acids. All breeds showed similar welfare indicators, with consistent haematological values and feather corticosterone concentrations (P > 0.05). While Millefiori Piemontese displayed higher slaughter weight (on average, + 9.10%; P = 0.046) and triglycerides (on average, + 21.6%; P = 0.021), most intestinal health traits remained comparable among breeds (P > 0.05). Analysis of intestinal bacterial composition revealed distinct microbial profiles among the three breeds. Several families and genera varied significantly in relative abundance, indicating breed-associated differences in gut microbiota structure, although overall diversity and fermentation patterns remained similar. These findings provide a useful baseline for future research on the potential role of these breeds in low-input, sustainable farming systems.