Analysis On Stalk Components And Silage Nutritional Value Of High Oil Corn

The objectives of this study were:(1) to investigate the feasibility and methods of measuring quality of corn stalk with near infrared reflectance spectroscopy (NIRS) by using 151 powdery silage and air-dry stalk samples of maize hybrids(2) to study the yield, silage nutrition component and digestibility of different varieties and mature stage corn stalk with 18 high-oil and 12 normal varieties. The results were as follows:1. The calibration equations for quantitative determination of cellulose,lignin,ADF and mineral concentration of corn stalk were developed in China by partial least square regression (PLS) of chemical values on NIRS data and tested through both cross and external validation. The calibration coefficients of determination (R2cal) between NIRS and chemical values are 96.68, 89.49, 94.73, 92.1 respectively,the external validation coefficients of determination (R2cval) ranged from 80.77 for mineral to 94.55 for ADF, while the root mean square error of prediction (RMSEP) from 1.34g/kg for cellulose to 12.5g/kg for ADF. In addition, 15 additional samples of com stalk excluded in calibration and validation sets were used to evaluate the calibration equations' performance. Coefficients of correlation(R) between NIRS predicted values and chemical values were 0.99(cellulose concentration), 0.99(ADF concentration), 0.98(lignin concentration) and 0.93(mineral concentration). So,this study showed that NIRS was feasible to determine nutrition component of corn stalk.2.Dry matter(DM%) of all varieties ranged 25%~70%, single stalk fresh weight ranged 389.31~ 1358. 17g and single stalk dry weight ranged 146.28~362.75g. Average stalk fresh weights of different maturity were different and the highest at 3/4 milkline,next at 2/4 milkline ,the least at 4/4 milkline. High-oil corn stalk had higher water-solubility sugar concentration(WSC)compared with that of normal corn.3. Hybrid, and maturity had obvious effects on the chemical ingredient and digestibility of stalk in this experement.And two-third of anterior fifteen high digestibility varieties were high-oil corn.4.Significant negative correlation were found between digestibility and ADF, lignin, cellulose, mineral concentration and lignification degree(g/gADF) of silage stalk, and coefficients of correlation between ADF, lignification degree, mineral concentration and digestibility were -0.63,-0.60,-0.60 respectively.