Stable Isotopes And Mineral Elements Traceability Of Pasturing And Barn Feeding Cattle Meat In Inner Mongolia

Stable isotopes and mineral elements of beef in Inner Mongolia lack systematic evaluation.A total of 97 longissimus dorsi muscle samples of pasture grazing and barn feeding cattle were collected from 8 banners/counties distributing from east to west in Inner Mongolia for the determination of the?¹³C and?¹⁵N values and 14mineral elements,and descriptive statistics analysis,cluster analysis and linear discriminant analysis(LDA)were conducted on the data obtained.Models of select effective indicators and data processing methods were established to discriminate pasturing beef from barn feeding.Results showed that stable isotopes and mineral elements were different in feeding systems and geographical origins.The?¹³C and?¹⁵N values of grazing beef were(-20.89±3.09)‰and(7.45±1.71)‰,respectively.The?¹³C value and?¹⁵N values of barn feeding were(-13.97±4.55)‰and(4.79±1.20)‰.Carbon and nitrogen stable isotope scatter plot and mineral elements principal component analysis(PCA)plot show that two feeding systems can be separated obviously.Clustering of geographical origins is consistent with clustering of feeding systems,grazing and barn feeding banner/county clustering separately.Further analysis of mineral elements can better separate pasture grassland of Hulunbeier and Xilingol,barn feeding banner/county of Horqin Left Wing Rear Banner,Baarin Right Banner,Zhenglan Banner and Uxin Banner were also separated.The estimation and validation of the combination of stable isotopes and mineral elements showed that the accuracy of identifying grazing and barn feeding beef was100%,that of beef between grazing cities was 100%,and that of beef between barn feeding counties was 100%and 98.6%,respectively.The traceability effect was better than single traceability technology.The effective order of different indexes in identifying feeding systems of beef is stable isotopes combined with mineral elements>stable isotopes>mineral elements,and the effective order in identifying geographical origins of beef is stable isotopes combined with mineral elements>mineral elements>stable isotopes.In paired analysis of variance and paired t-test,no significant differences in the stable isotopes and mineral elements were observed in feeding systems and geographical origins,indicating that the conventional statistics are not sensitive to the overall stable isotopes and mineral elements comparison.?¹⁵N,Ni,Sr and Tl of pasturing beef were significantly higher than that of barn feeding beef,while?¹³C,Se,Rb and Cs of barn feeding beef were significantly higher than that of pasturing.Se of beef increased from east to west,while Mn decreased from east to west.Soft independent modeling of class analogies(SIMCA)model was established by?¹³C,?¹⁵N,Se,Rb and Sr,and the accuracy of internal and external verification were 100%.In a word,the feeding methods and geographical sources of cattle in Inner Mongolia can be distinguished by stable isotopes and mineral elements.