Evaluating The Nutritive Values Of Corn Stover By Using The FTIR Technology

The objective of this study was to explore nutritive values and molecular structures and whether there was a relationship between nutritive values and molecular structures in different sections of corn stover. Whether we could use the Fourier transform infrared spectroscopy(FTIR) to assess nutritive values of different sections of corn stover. The nutritive values of different sections of corn stover(ear husk, leaf blade, leaf sheath, stem rind and stem pith) were determined by conventional chemical analysis, Cornell Net Carbohydrate and Protein System(CNCPS) and in situ rumen degradation test. At the same time, the spectral parameters of molecular structures were analyzed by using the FTIR technology. And then explore the relationship between them. The results showed that:(1) There were significant differences in nutritive va lues of different sections of corn stover(P<0.05). The leaf blade had the highest level in CP and NDICP, the stem pith had the highest content of NPN and SCP, the ear husk had the highest level of NDF and hemi-cellulose, and the stem rind had the highest content of ADF and cellulose. Combined with CNCPS sub-fractions and in situ rumen degradation parameters, the ear husk, leaf blade and stem pith had a higher nutritional values and the stem rind had the lowest nutritional values in different sections of co rn stover.(2) The protein molecular structures and carbohydrate molecular structures significantly differed among all corn stover sections; Among them, the leaf blade had the highest height ratio of α-helix to β-sheet which could indicate the leaf blade had a higher protein nutritional values in different sections of corn stover.(3) The correlations between molecular structures and nutritional values were found by using correlation analysis and regression analysis. The results showed that the content of CP(R2=0.80, P<0.0001), NDICP(R2=0.95, P=0.0001), ADICP(R2=0.60, P=0.0002), PC(R2=0.65, P=0.0004) and DMED(R2=0.48, P=0.0015) might be predicted by using the height ratio of Amide I to Amide II and the height ratio of α-helix to β-sheet and peak values of Amide II. We could also use the height ratio of CHO peak 1 to 3, peak 2 to 3, and the area ratio of CELC to CHO to predict the content of CHO(R2=0.62, P<0.0001), NFC(R2=0.63, P<0.0006), cellulose(R2=0.64, P<0.0001), CA(R2=0.66, P=0.0003), CB2(R2=0.61, P=0.0001) and NDFED(R2=0.39, P=0.0060).All in all, there were correlations between protein, carbohydrate molecular structures and their nutritive values in different sections of corn stover. And the protein and carb ohydrate compositions could be analyzed and predicted quickly by using the FTIR technology. Among them, the estimate effects of protein nutritive values by using protein molecular structures were better.