Abstract: A study was undertaken to analyze the effect of hay moisture,bale tightness,and urea preservation on the baled alfalfa hay nutritive value.Results are as follows:After the first crop of alfalfa forage hay of 33.08% moisture content had been baled with three different degrees of compactness-densely,medium-densely,and loosely-and stored for 100 days,its contents of acid detergent fiber(ADF),neutral detergent fiber(NDF) and crude fiber(CF) decreased with less compactness of the bale.When the moisture content of the baled hay was of 21.16%,the hay contents of ADF,NDF and CF increased with the looseness of the bale.The temperature of high moisture content(33.08%) alfalfa bales rose during storing,also with the degree of bale tightness.The more compact the hay in the bales,the higher the temperature rose,and the longer the high temperature persisted.To add urea preservative to the high moisture,tightly baled alfalfa could lower down its temperature within a relatively short time.However,alfalfa bales with 21.16% water content showed no increased temperature. To store quality alfalfa hay,it is preferable to add 2.5% urea preservative to hay bales of moisture content of 33.08% and bale tightness of 250.3 kg/m³.Alfalfa hay quality is ensured with low moisture content of 21.16%,and bale tightness of 393.6 kg/m³.

Key words: Alfalfa(Medicago sativa L.), Baled hay, Moisture content, Bale compactness, Urea preservative

摘要： 研究不同含水量、密度和尿素处理对苜蓿草捆质量的影响,结果表明:第一茬苜蓿打捆贮藏100 d后,在苜蓿含水量为33.08%条件下,随草捆密度减少,其酸性洗涤纤维、中性洗涤纤维、粗纤维含量降低;在苜蓿含水量为21.16%条件下,随草捆密度减少,其酸性洗涤纤维、中性洗涤纤维、粗纤维含量升高。苜蓿含水量33.08%的不同处理草捆都有升温现象,草捆温度随密度增加而升高;高温持续时间也不同,密度增加高温持续时间长;添加尿素具有降低草捆温度并缩短高温持续时间的作用。苜蓿含水量22.16%的不同处理草捆都无升温现象发生。为了获得优质苜蓿草捆,应以制作高水分低密度加尿素(33.08%、250.3kg/m³、2.5%)和低水分高密度(21.16%、393.6 kg/m³)草捆为主。

关键词: 苜蓿, 草捆, 含水量, 密度, 尿素