Effects of polyphenols from involucres of Castanea mollissima Blume on the nutritional quality and bacterial community of high-moisture ear corn.

High moisture ear corn (HMEC) is widely used in dairy cow diets, but its high moisture contentcan cause protein hydrolysis during fermentation. This study evaluated the effects of polyphenolsextracted from the involucres of Castanea mollissima Blume (PICB) on the nutritional quality andbacterial communities of HMEC at two moisture levels: low moisture (LM, 40%) and high mois-ture (HM, 45%), using a 2 � 4 factorial design. HMEC was treated with 0% (CON), 0.1% (PICB1),0.15% (PICB2), or 0.2% (PICB3) PICB. Lactic acid bacteria (15 mg/kg) were applied before ensiling.After 60 days of fermentation, crude protein (CP), dry matter (DM), lactic acid (LA), acetic acid(AA) and ammonia nitrogen (NH3-N) were highly significantly higher (p < 0.01) in LM than thosein HM. DM and CP contents were also highly significantly higher (p < 0.01) in LMPICB3 than thosein LMCON. LA content of LMPICB3 was highly significantly higher (p < 0.01), while neutral deter-gent fibre (NDF) and NH3-N content were highly significantly lower (p < 0.01) than other treat-ments in LM. DM, CP and LA contents were significantly higher (p < 0.01) in HMPICB3 comparedto other treatments in HM. Microbial analysis revealed that Lactobacillus was most abundant inLMPICB3, positively correlated with LA. In contrast, Pantoea and Serratia were positively correlatedwith NH3-N content. Klebsiella was negatively correlated with CP and LA contents. Inconclusion, 40% moisture content combined with 0.2% PICB addition resulted in optimal fermen-tation quality in HMEC, demonstrated by increased LA and CP contents along with reduced NH3-N contents