导　　师： 邵涛

学科专业： I0503

授予学位： 硕士

作　　者： ;

机构地区： 南京农业大学

摘　　要： 试验以生长第一年的紫花苜蓿/(Medicago sativa L./)为原料,进行了四个方面的试验研究：1.紫花苜蓿单独青贮发酵品质动态变化的研究；2.用不同比例的意大利黑麦草与紫花苜蓿混合青贮对紫花苜蓿青贮发酵品质的影响；3.添加绿汁发酵液/(Previously Fermented Juices, PFJ/)、糖蜜/(Molasses/)和绿汁发酵液+糖蜜/(PFJ+M/)对紫花苜蓿青贮发酵品质的影响；4.不同凋萎水平对紫花苜蓿青贮发酵品质的影响。 试验结果表明：紫花苜蓿单独青贮发酵品质较差,很难调制成优质青贮饲料,因此需采用混贮、添加剂、凋萎等处理方法以提高其青贮发酵品质。 紫花苜蓿与意大利黑麦草按照鲜重质量比2：8/(H-1/)、3：7/(H-2/)、4：6/(H-3/)、5：5/(H-4/)混合青贮。混贮后各组青贮料的pH值在青贮30天时都降到4.31以下,其中H-1和H-2组的pH值小于4.2,达到了优质青贮饲料的标准,且四个处理组都具有较低的氨态氮／总氮、较高的乳酸和水溶性碳水化合物含量。综合评定各组青贮料的发酵品质,紫花苜蓿与意大利黑麦草的质量比为30/%：70/%的H-2处理的pH值为4.11,且具有较高的乳酸含量/(84.12gkg-1DM/)、最低的氨态氮／总氮和最高的水溶性碳水化合物残留/(8.88gkg-1DM/),青贮效果最好。 添加绿汁发酵液、糖蜜的试验结果表明,添加糖蜜以及混合添加糖蜜与绿汁发酵液的处理与对照相比,都显著降低了青贮料的pH值和AN／TN,提高了青贮料中的乳酸和水溶性碳水化合物含量,说明添加糖蜜以及混合添加糖蜜与绿汁发酵液能够明显改善紫花苜蓿的发酵品质。但单独添加绿汁发酵液并没有改善紫花苜蓿的青贮发酵品质。 凋萎处理各组的pH值在整个青贮过程中都未能下降到4.8以下,对照组的pH值显著低于各凋萎处理组。不同含水量的处理组之间,W-3组的pH值显著低于W-1和W-2组/(P<0.05/)。在青贮30天时,对照组的乳酸含量显著低于三个凋萎处理组/(P<0.05/),而三个凋萎处理组的乳酸含量随原料水分含量的下降而呈下降趋势。乙酸随水分含量的降低而呈下降的趋势,对照组的乙酸含量显著高于其他三组/(P<0.05/),三个凋萎处理之间差异显著/(P<0.05/),其中W-3组的乙酸含量最低为23.41gkg-1DM。对照组的乳酸／乙酸值显著低于三个凋萎处理组/(P<0.05/),且三个凋萎处理之间差异显著/(P<0.05/),其中W-3组的乳酸／乙酸值最高为0.27。AN／TN值随着青贮料干物质含量的增加而下降,粗蛋白质的损失以W-3组为最低,对照组最高。四个处理组水溶性碳水化合物的消耗,除W-1组外,其余各组随水分含量的下降而呈下降趋势,但W-1组与对照组之间并没有显著差异。综合评定各组青贮料的发酵品质,干物质含量为412.7gkg-1FW的W-3处理具有相对较高的乳酸含量、最低的氨态氮／总氮和最多的水溶性碳水化合物残留,青贮效果最好。 This study was to determine the effects on fermentation quality of alfalfa /(Medicago sativa L./) silage. There were four experiments in this study with laboratory-scale silo. Experiment I:The dynamical fermentation quality of alfalfa and Italian ryegrass silages were studied. ExperimentⅡ:Effects of adding previously fermented juices /(PFJ/), molasses /(M/) and PFJ+M on the fermentation quality of alfalfa silage; ExperimentⅢ:The fermentation quality of alfalfa silage with Italian ryegrass mixed; ExperimentⅣEffect of wilted on fermentation quality of alfalfa silage. The results were as follows: Exp.1:The silos were opened on 0.5,1,1.5,2,3,5,7,14 and 30 days of ensiling in this experiment. The dynamic fermentation quality showed that the alfalfa silage had low fermentation quality during ensiling. In Exp.2:Alfalfa and Italian ryegrass were chopped and than were mixed in ratios of 2:8,3:7,4:6,5:5 /(fresh weight basis; denoted H-1, H-2, H-3, and H-4, respectively/) and ensiled in laboratory silos, they were opened on 1,3,5,7,14 and 30 days of ensiling. The mixed silage reduced pH and NH3-N//total N /(P<0.05/) during 30 days of ensiling, and increased the contents of LA and WSC /(P<0.05/). In the 30day ensiling process, the H-2 had high content of LA /(84.12 gkg-1DM/), lowest content of AN//TN and highest content of WSC /(8.88 gkg-1DM/), it suggested that H-2 was the best mixed rate. In Exp.3:The dynamic effect of fermentation was studied on alfalfa silage with adding Previously fermented juice /(PFJ/), Molasses /(M/) and PFJ+M. Based on the results the pH and AN//TN of alfalfa silage was significantly /(P<0.05/) decreased and the contents of LA and WSC significantly /(P＜0.05/) increased with M and PFJ+M treatments as compared with control, M and PFJ+M treatments can improve the quality of alfalfa silage. But single previously fermented juices additive did not improve silage quality in this experience. In Exp 4:There were four treatments:control and three wilted levels. All wilted treatment silage had higher pH of 4.8 during ensiling as compared with control, and the W-3 was lower than the other wilted silage /(P<0.05/). On 30th day, the pH value, LA, LA//AA of the control was significantly /(P＜0.05/) lower than all three wilted treatments, the AA content and AN//TN significantly /(P<0.05/) decreased in wilted silage treatments. During the 30 days of ensiling, the W-3 treatment /(DM=412.7gkg-1 FW/) was considered better than other treatments for the high LA content, lowest AN//TN and highest WSC content.

关 键 词： 紫花首蓿 添加剂 混贮 凋萎 发酵品质

分 类 号： [S5]

领　　域： [农业科学]