Effects of intelligent housing systems on meat quality and flavor of different cuts of yellow-feathered broiler chickens.

This study systematically compared the differences in objective indicators of eating quality, texture properties, free amino acids, volatile flavor compounds, and metabolomic profiles in breast and thigh muscles of yellow-feathered broiler chickens reared under an environmentally controlled, enclosed intelligent cage system and a floor litter rearing system, and correlation analyses among these parameters were conducted. The results showed that, compared with floor rearing, cage rearing significantly reduced L* values while significantly increasing a* and b* values in both breast and thigh muscles (P < 0.05). Free amino acid and volatile flavor compound analyses revealed diametrically opposite trends between the two muscle types: cage rearing significantly decreased the contents of free amino acids and volatile flavor compounds in breast muscle, yet markedly increased their levels in thigh muscle (P < 0.05). Ser, Glu, Ala, Val, Ile, Phe, Lys, and Arg were identified as important amino acid contributors to chicken meat flavor under both housing systems, with Lys playing the dominant role in breast muscle and Glu being the most prominent contributor in thigh muscle. Hexanal, ethanol, 2-butanone, and pentanal were identified as the key volatile flavor compounds discriminating the flavor profiles between the two housing systems. Metabolite analysis revealed that meat quality-related metabolites, including propionylcarnitine, isoleucyl-asparagine, alanylarginine, ADP-ribose, and 4-aminobutyric acid, were downregulated in breast muscle, whereas umami-related metabolites such as glutamic acid, N-acetylasparagine, and 4-guanidinobutanoic acid were upregulated in thigh muscle. Purine metabolism, alanine-aspartate-glutamate metabolism, and nucleotide metabolism were identified as the key metabolic pathways contributing to flavor divergence between the two housing systems, and inosine emerged as a potential metabolic marker for discriminating meat quality differences between cage-reared and floor-reared chickens. Correlation analysis demonstrated that acylcarnitine metabolites, including (9Z)-3-hydroxydodecenoylcarnitine, 2-octenoylcarnitine, 3-hydroxyhexanoylcarnitine, 3-hydroxyoctanoyl carnitine, and 6-keto-decanoylcarnitine, exhibited broad-spectrum significant positive correlations with bitter-tasting amino acids and core volatile flavor compounds, whereas bile acid metabolites displayed significantly negative correlations (P < 0.05). These findings suggest that acylcarnitine accumulation may promote the enrichment of bitter amino acids while concurrently suppressing the synthesis of characteristic aroma compounds. In conclusion, although the intelligent cage housing system partially diminished the meat quality of breast muscle, it markedly enhanced the nutritional value and flavor quality of thigh muscle, which may represent a key target site for meat quality improvement under cage rearing conditions. This study systematically elucidates the regulatory mechanism of rearing systems on meat quality and flavor of yellow‑feathered broilers from multiple perspectives, providing a theoretical basis for the optimization of rearing modes for yellow‑feathered broiler production.