不同含水量对不同生长时期的王草青贮品质的影响

摘要

本试验旨在研究不同含水量与不同生长时期对王草青贮发酵品质的影响,探究优质王草青贮饲料的最适生长时期与最佳含水量.试验分别对生长30,50,70,90 d的王草调制成3个水分梯度(高水分＞75％、半干:65％～75％、低水分＜65％),贮藏35 d后开罐,分析其pH值、挥发性脂肪酸、氨态氮、可溶性碳水化合物等成份的含量.结果表明:半干青贮能获得较低的pH值和较高的乳酸含量,经晾晒处理的王草青贮料生成的PA、BA较少,AN/TN值也较低.王草的生长时期越久其DM、WSC、NDF与ADF的含量越高,而CP的含量变化则随成熟度增加而降低.半干处理还能增加生长30 d与50 d王草青贮料的CP含量.综合考虑生产实践中选用生长50 d的王草进行半干青贮,既可获得优质的青贮料又能保证有较高的产量和营养品质.%The effects of different moisture content on the quality of King Grass at different growing stages and the best way to ferment King Grass silage were investigated.King grasses were stored with three moisture contents(high moisture＞75％,middle moisture:65％～75％,low moisture＜65％).The fermentation qualities(pH value,VFAS,the contents of ammonia-N and WSC and other chemical composition)were analyzed after storing for 35 days.The results showed that middle moisture treatment resulted in a lower pH and a higher lactic acid.The wilting treatment led to a reduction in propionic acid,butyric acid and AN/TN value.The longer growing time of King Grass is,the higher dry matter,the water soluble carbohydrate,the neutral detergent fiber and the acid detergent fiber content are,but the change of crude protein was the contrary.These results suggest that choosing the King grass at 50 days for half dry silage can not only get high quality silage but also ensure a higher yield and nutritional quality.