Evaluation of whole-plant maize silage quality in different regions of China based on principal component and silage quality grading score analyses

The aim of this study was to investigate the quality of whole-plant maize silage stored in cellars in different regions of China using principal component and whole-plant maize silage quality grading score (CSQS) analyses, and to provide a theoretical basis for the evaluation and production of whole-plant maize silage. The nutrient composition and fermentation quality of whole corn silage in different regions were significantly different (P < 0.05). The CSQS was used to classify 17 provinces into five grades with respect to four nutritional indicators (crude protein, starch, crude fat content, and neutral detergent fiber digestibility_30h), and two fermentation indicators (ammonia and lactic acid contents). The whole-plant corn silage quality in different regions was found to descend in the following order: (CSQS = 64.42) in the Yellow and Huaihai regions (Shandong, Hebei, Henan, and Anhui); (CSQS = 59.72) in the northeast region (Heilongjiang, Jilin, Liaoning, and Inner Mongolia); (CSQS = 58.99) in the northwest region (Shaanxi, Shanxi, Qinghai, Gansu, Xinjiang, and Ningxia); (CSQS = 52.87) in southwest China (Yunnan and Guizhou); and (CSQS = 48.41) in south China (Guangxi). Among these regions, the best quality silage was made in the Yellow and Huaihai regions. Principle component analysis revealed neutral detergent fiber digestibility, crude fiber, and organic acids as the three principal components, with a cumulative contribution of 83.201%, which reflected the comprehensive quality of whole-plant maize silage.