Comparative morphological and lipidomic profiling of abdominal adipose tissue in Beijing You chickens at different ages and Ross 308 broilers

This study aimed to compare fat deposition, muscle tissue structure, and abdominal fat lipid metabolism among 150-day-old Beijing You chickens, 450-day-old Beijing You chickens, and 150-day-old Ross 308 broilers. Slaughter performance analysis revealed that Beijing You chickens exhibited significantly higher fat deposition than Ross 308 broilers, with continuous accumulation observed with increasing age. Histological observations showed that the breast muscle fibers of Beijing You chickens were significantly smaller than those of Ross 308 broilers of the same age, while the diameters of abdominal adipocytes were significantly larger and increased further with age. Lipidomic profiling of abdominal fat identified 613 significantly different lipid species between Beijing You chickens and Ross 308 broilers, and 250 lipid species differing between the two age groups of Beijing You chickens. Among them, 123 lipid species were differentially abundant in both comparisons, mainly enriched in glycerophospholipid and sphingolipid metabolism pathways, suggesting their key roles in lipid metabolic remodeling. These findings reveal distinct differences in lipid metabolism and muscle development among chicken breeds and provide a theoretical basis for understanding the molecular mechanisms underlying flavor, tenderness, and metabolic regulation, as well as a valuable reference for molecular breeding of high-quality poultry.