麻叶荨麻与玉米粉混贮对青贮品质的影响

为解析添加玉米粉对麻叶荨麻青贮发酵品质和养分保存效果的影响,将麻叶荨麻与玉米粉5∶1混合调制青贮饲料,将其DM含量提高到310 g/kg,以麻叶荨麻单独青贮作为对照。每个处理18个重复,室温袋贮60 d后开封取样,测定青贮发酵品质和营养成分及消化率,并分别在贮藏后第0,3,5,15,20和60天调查pH、有机酸、氨态氮的动态变化。结果表明,与玉米粉混合青贮通过快速降低pH和提高乳酸含量而明显加快了麻叶荨麻的发酵进程,发酵前15 d,混贮组pH下降速率和乳酸累积速率较单贮组快;混贮组显著降低了(P<0.05)pH、氨态氮、乙酸、丁酸及NDF和ADF含量,显著提高了(P<0.05)乳酸、水溶性碳水化合物(WSC)含量、费氏评分及干物质与纤维组分的体外消化率;脂肪含量在两个处理之间无显著差异。以上结果表明,麻叶荨麻与玉米粉以5∶1混合青贮能够成功保存麻叶荨麻的高品质营养特性,从而生产高品质青贮饲料,同时还能改善家畜对它的利用效率。

Effect of corn flour on the quality of Urtica cannabinasilage

To investigate the effect of corn flour (CF) on the nutritive value ensiled Urtica cannabina or hempleaf nettle (HN),CF was added to fresh HN using a 1∶5 mixture (CF∶HN) silage. Dry matter (DM) was adjusted to approximately 310 g/kg. Silage without CF was used as a control. Silage was packed in plastic bags; each treatment had 18 replicates. The fermentative quality, nutrient component and in vitro digestibility of silages were assessed after 60 days of ensiling at ambient temperature. The pH, NH₃-N and organic acids of silages were measured after 0, 3, 5, 15, 20, and 60 days. The results revealed that CF treatment significantly (P<0.001) accelerated silage fermentation by reducing pH and increasing lactic acid concentration. In the first 15 days of fermentation, the silages with CF treatment tended to have a faster rate of pH decline and lactic acid accumulation than the silage without CF treatment. This study also showed that the CF treatment silage had significantly lower (P<0.05) pH, NH₃-N, acetic and butyric acids, neutral detergent fiber (NDF) and acid detergent fiber (ADF) than silages without CF treatment after 60 days of ensiling. In contrast, CF treated silages contained significantly higher (P<0.05) lactic acid, water-soluble carbohydrate (WSC) and Flieg point values, as well as higher in vitro digestibility of DM, NDF and ADF. There was no difference in crude fat between the CF treatment and the control treatment. In conclusion, CF improved the nutritive value of HN silage, potentially increasing utilization by livestock.