水分和添加剂对紫花苜蓿青贮品质的影响

Effects of moisture and additives on feed quality of alfalfa silage

分别对含水量为54.27%和42.67%的紫花苜蓿设不添加、添加乳酸菌＋葡萄糖、纤维酶剂和饲料益菌素（suk B）进行青贮,在贮藏后的第65天开封,分析各处理青贮饲料的发酵品质和主要营养成分含量。以探讨不同水分和添加剂及其互作对紫花苜蓿（Medicago sativa）青贮品质的影响。结果表明,各处理组紫花苜蓿青贮后的感官评分均在13.6-16.1,感官评定均为优良青贮饲料。以添加纤维素酶组的感官评分最高,总分为16.1,达优质青贮饲料。水分和添加剂对苜蓿青贮营养成分含量均没有显著影响（P〉0.05）;但两因素的交互作用可显著提高紫花苜蓿青贮后的嗅觉评分（P〈0.05）,54.27%的含水量较42.67%的青贮效果更好,可显著降低青贮pH值（P〈0.05）,改善青贮品质,这说明低水分紫花苜蓿可不用添加剂直接青贮,但水分过低,不利于降低酸度。添加剂只在适宜水分条件下才可改善紫花苜蓿青贮发酵品质。

Two factors （moistureX additive） and eight levels design were used to investigate the effects of moisture and additives on quality of alfalfa silage. Three additives were used in the present study, which was lactic acid bacteria＋glucose, cellulose enzyme, and beneficial bacteria（suk B）. The alfalfa containing 54.27% and 42.67% of water were supplemented with or without one of the three additives and were then ensiled in polythelene bags for 65 days, respectively. Each treatment repeated three times. The results showed that evaluation scores of each treatment were between 13.6 and 16. 1 which suggested that all of them were good silage. Silage with enzyme cellulose group had the highest sensory score with 16.1. Moisture and additives, separately, has no effect on nutritional ingredients of alfalfa silage, however, the interaction of these two factors significantly improved the smell scores （P〈0. 05）. The alfalfa containing 54.27% moisture had significantly low level of pH which improved silage quality. All of these results suggested that low moisture alfalfa can directly be made to silage without any additives, however, it was unfavourable for silage acidity reduction if the moisture was too low. Only under the appropriate moisture conditions, additives can improve alfalfa silage fermentation quality.