The Effects of Different Clipping Stubbles and Harvest Times in a Day on Fermentation Quality and in Vitro Ruminal Fermentation Characteristics of Alfalfa Silage

The objective of this study was to determine the effects of different diurnal harvest times and clipping stubbles on alfalfa silage quality, furthermore, to evaluate its feeding value. Two-factors were designed in this study. Budding stage alfalfa was harvested twice at 08 : 00 (AM), 13 : 00 (M) or 18:00 (PM) on a sunny day. Silages were prepared using a laboratory scale system without wilting, and stored at ambient temperature for 45 days. Then the samples were collected and in vitro gas production method was used to evaluate their feeding value. The alfalfa silage fermentation quality and in vitro digestibility were analyzed. The results showed that the relative feed value (RFV), in vitro dry matter digestibility (IVDMD), the in vitro volatile fatty acids (VFA) contents and gas productions of the first cutting alfalfa silage was significantly higher (P < 0. 05) than those of the second cutting. Compared to the AM-cut alfalfa silage, PM-cut alfalfa silage had higher (P < 0. 05) dry matter (DM) content and IVDMD. These results suggested that the first cutting alfalfa and the decision to delay the harvest time to the M or PM benefited for good silage fermentation and feeding value.