Effects of silage fermentation promoter and harvest stage on nutrient quality of whole silage maize

This study aimed to investigate the effects of silage fermentation promoters on the nutritional quality of whole-plant corn silage at different harvest stages. In 2018, ‘Yu silage 23’ was used as the test material, and three treatments (control, Sila-Max, and Sila-Mix) were set at 1/2, 2/3, and 3/4 milk-line periods, repectively. After 60 days of silage, openbag sensory evaluation and sampling were conducted to determine nutritional quality. The results showed that the silage fermentation promoter had no significant effect on the sensory evaluation of the whole plant silage corn (P > 0.05), which significantly affected ammonia nitrogen (NH₃-N), lactic acid (LA), acetic acid (AA), dry matter recovery (DMR), dry matter (DM), crude protein (CP), and water-soluble carbohydrate (WSC) content (P < 0.01), as well as the pH, butyric acid (BA), and starch (ST) content (P < 0.05). The delayed harvest period had a significant impact on the whole plant corn silage LA, AA, BA, DMR, DM, CP, ether extract (EE), crude ash (Ash), neutral detergent fiber (NDF), acid detergent fiber (ADF), ST, WSC, 48 h in vitro dry matter digestibility (IVDMD_{48 h}), 48 h in vitro neutral detergent fiber digestibility (IVNDFD_{48 h}), and total digestible nutrients (TDN) (P < 0.01), as well as the pH (P < 0.05). The gray correlation results show that the stage when the milk-line is at 2/3 is suitable for harvesting, and the silage fermentation promoter Sila-MIX is suitable for promotion and use in production practice.