Volume 10,Issue 7
Silage corn feed is an important source of roughage for cattle and sheep breeding. Its pH value can quickly reflect the quality of feed and is one of the main indicators for evaluating the fermentation quality of feed. In this study, the pH value of silage corn feed was non-destructively and rapidly detected based on near-infrared spectroscopy analysis technology. The silage corn feed of dairy farms in Tai’an City, Shandong Province was taken as the research object. The spectra of 855~1890 nm of samples were collected based on a miniature near-infrared spectroscopy acquisition system, and the pH value prediction model of silage corn feed was established by combining chemometrics methods. Firstly, a miniature near-infrared spectroscopy acquisition system was introduced. The system was used to collect the near-infrared spectral data of 260 silage corn feed samples. The near-infrared spectral data were preprocessed by standard normal transformation, moving mean filtering, and multiple scattering correction. The wavelength was optimized by algorithms such as elimination of uninformative variables, competitive adaptive reweighted sampling algorithm, and variable iterative space shrinkage. The support vector regression (SVR) model based on snake optimization (SO) was used. The model was established by combining the pH value of the leaching solution of silage corn feed with the pH meter. The results show that the full-band modeling based on multiple scattering correction (MSC) pretreatment is the best, the modeling effect of the characteristic wavelength selected based on variable iterative space shrinkage approach (VISSA) is the best, and the modeling effect of MSC-VISSA-SO-SVR model is the best, and the correction correlation coefficient is 0.990531. The corrected root mean square error is 0.083545, the predicted correlation coefficient is 0.980487, and the predicted root mean square error is 0.127718. The results of this study show that the combination of MSC-VISSA-SO-SVR model based on micro near-infrared spectroscopy acquisition system can provide a reference for non-destructive detection of pH value of silage corn feed by near-infrared spectroscopy.