Proteomic-metabolomic combination analysis reveals novel biomarkers of meat quality that differ between young and older ducks

In order to explore the difference and its underlying mechanism between young and older ducks, 60-day-old (D60) and 300-day-old (D300) of young ducks and 900-day-old ducks (D900) of older ducks were selected and studied. HE staining indicated that breast muscle fibers in the D900 group were more inseparable than D60 and D300 groups and the greater redness were showed in D300 and D900 groups. Quantitative proteomic analyses were conducted to further identify differences between young and older ducks that 61 proteins overlapped in the comparative analysis of the D900 vs. D60 and D900 vs. D300 groups. Furthermore, metabolomics analysis from the D900 group showed marked differences from the results of the D60 and D300 groups in 31 unique metabolites. In particular, lower guanosine, hypoxanthine, guanine, and doxefazepam levels indicated the increased nutritional value of older ducks. Integrated proteomics and metabolomics analysis showed that purine metabolism was specifically enriched, indicating that NME3, RRM2B, AMPD1, and AMPD3 might mainly affect meat from older ducks. In conclusion, our results indicated that meat from 900-day-old ducks possessed a unique biochemical signature that could provide candidate biomarkers to distinguish young ducks from older ducks.