Abstract: In order to investigate the effect of citric acid on the mildew control within alfalfa hay and determine the optimal dosage,alfalfa hay after air drying was used as the material in this experiment,and different amounts of citric acid (0%,1%,2% and 3%) were added. After air drying to 20% water content,the alfalfa hay was baled and stored,and sampled on 0,20,30,40,50,60 days to test the changes of its nutritional quality and the quantity of mold within it. The results showed that the contents of crude protein (CP),soluble carbohydrate (WSC),crude fat (EE) and relative feeding value (RFV) were decreased gradually with the storage processing;while the content of neutral detergent fiber (NDF) and acidic detergent fiber (ADF) were increased gradually;the amount of molds in alfalfa bales showed an exponential growth trend. Compared with the control-check,2% and 3% citric acid treatment significantly increased CP content and RFV at 60 days of storage (P<0.05);and the amount of molds in different storage periods were significantly reduced (P<0.05). According to the comprehensive evaluation by the membership function,when the storage period was 60 days,the comprehensive value of the alfalfa hay under the 3% citric acid treatment was the highest. Therefore,addition of 3% citric acid to alfalfa hay has the best anti mildew effect.

Key words: Citric acid, Fungicide, Nutritional quality, Membership function

摘要： 为探讨添加柠檬酸对苜蓿(Medicago sativa)干草防霉效果的影响，并确定其最佳用量，本试验以翻晒过后的苜蓿干草为材料，添加不同量的柠檬酸(0%，1%，2%与3%)，晾晒至20%含水量后打捆贮藏，于贮藏0，20，30，40，50与60 d取样测定其营养品质与霉菌数量的变化。结果表明:随着贮藏时间的延长，粗蛋白质(Crude protein,CP)、可溶性碳水化合物(Water soluble carbohydrate，WSC)、粗脂肪(Ether extract，EE)含量和相对饲喂价值(Relative feeding value，RFV)呈逐渐降低的趋势，中性洗涤纤维(Neutral detergent fiber，NDF)与酸性洗涤纤维(Acid detergent fiber，ADF)含量呈逐渐增加的趋势，霉菌数量呈抛物线升高趋势。与对照组相比，添加2%与3%柠檬酸，贮藏60 d的CP含量和RFV值显著增加(P<0.05)，不同贮藏时期的霉菌数量显著降低(P<0.05)。通过隶属函数综合评价发现，贮藏期为60 d时，3%柠檬酸处理的综合价值最高。因此，添加3%柠檬酸至苜蓿干草中，防霉效果最好。

关键词: 柠檬酸, 防霉剂, 营养品质, 隶属函数