Integrated Lipidomics and Metabolomics Reveal Stage-Dependent Differences in Flavor Precursor Composition Between Higher- and Lower-Body-Weight Beijing-You Chickens

Body weight variation within a breed may be associated with meat flavor in chickens, but its relationship with flavor-related precursor composition across developmental stages remains unclear. Here, integrated lipidomics and metabolomics were applied to compare breast muscle from Beijing-You chickens sampled from the same cohort at 90, 110, 130, and 150 d in a stage-wise design. At each stage, higher-body-weight (HBW) and lower-body-weight (LBW) groups were independently defined from the upper and lower tails of the body weight distribution at that age. A total of 440, 259, 161, and 324 differential lipids, as well as 491, 257, 291, and 402 differential metabolites, were identified at the four stages, respectively. However, only 23 lipids and 3 metabolites were shared across all stages, indicating that metabolic differences between the HBW and LBW groups varied markedly across developmental stages. Differential lipids were mainly distributed among phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine, while glycerophospholipid metabolism was consistently identified in both lipidomic and metabolomic analyses. Notably, a key transition was observed between 110 and 130 d, during which the predominant direction of PUFA-like differential lipids shifted from HBW to LBW predominance. Representative differential metabolites included N-acetyl-L-methionine, N-methyl-L-glutamic acid, and γ-glutamyl-5-hydroxytryptophan, suggesting alterations in amino acid- and peptide-related metabolism. Overall, these findings provide insight into stage-dependent variation in flavor-related precursor composition within a breed across developmental stages. However, their direct contribution to flavor remains to be validated.