Stable isotopes verify geographical origin of Tibetan chicken.

Due to the particularity of origin area, the yield and price of Tibetan chicken are different from those in the plain areas, which leads to chickens from the plains being disguised as Tibetan chickens. In present study, Tibetan chicken and chicken from other four provinces in plain areas were distinguished by stable isotopes and chemometric methods. The cross-validation rate was 97.6%. Secondly, correlation between mean δ13C, δ15N, δ2H and δ18O values in chicken samples and environmentalparameters was investigated. These indicators are closely related to geographical environment. δ13C and δ15N values were positively correlated with longitude (R = 0.955) and altitude (R = 0.796), respectively. δ18O and δ2H values were negatively correlated with latitude (R = 0.903) and altitude (R = 0.938), respectively. At last, we used stable isotopes to trace Tibetan chicken from the different area of Tibet. When four stable isotope ratios were combined, we can distinguish them.