div本研究由四个试验组成，以象草为青贮原料，采用添加剂青贮的方式，观察添加剂对象草青贮发酵品质动态变化的影响。添加剂分别是甲酸（2.2 ml kg-1<上标!>、4.4 ml kg-1<上标!>、6.6% ml kg-1 <上标!>FW）、纤维素酶（50 mg kg-1<上标!>、250 mg kg-1<上标!>-、500 mg kg-1<上标!> FW）、半纤维素酶（20 mg kg-1<上标!>、100 mg kg-1<上标!>、200 mg kg-1 <上标!>FW）、cornzyme酶（0.22 ml kg-1<上标!>、1.1 ml kg-1<上标!>、2.2 ml kg-1<上标!> FW）、葡萄糖（3% FW）及木糖（3% FW）。/div div试验一  添加不同水平甲酸对象草青贮发酵品质的影响/div div本试验主要研究添加甲酸添加量（0，2.2，4.4和6.6 ml kg-1<上标!>）和贮藏时间（0.5，1，2，3，5，7，14和30天）的对象草青贮发酵品质的影响。结果表明：在整个发酵过程中，对照组的象草青贮饲料pH值降低迅速，乳酸增加较快，氨态氮含量低于60 g kg-1<上标!>总氮，青贮发酵品质较好；与对照组相比，添加2.2、4.4和6.6 ml kg-1<上标!>甲酸在整个发酵过程中都使水溶性碳水化合物的下降速率减慢，且添加4.4和6.6 ml kg-1<上标!>甲酸的效果好于添加2.2 ml kg-1<上标!>甲酸（P<0.05）；青贮3天后，添加2.2 ml kg-1<上标!>甲酸的氨态氮和丁酸含量随贮藏时间的增加而较快增加，且均显著高于无添加、添加4.4和6.6 ml kg-1<上标!>甲酸（P<0.05）；添加4.4和6.6 ml kg-1<上标!>甲酸抑制乳酸、乙酸、丙酸和丁酸产生，使氨态氮含量都低于12 g kg-1<上标!>总氮。综上所述，青贮30天后，不添加甲酸的象草青贮饲料的发酵品质较佳，添加2.2 ml kg-1<上标!>降低了象草青贮饲料的发酵品质，添加4.4和6.6 ml kg-1<上标!>甲酸保存象草的效果最好。/div div试验二  添加三种不同水平细胞壁降解酶对象草青贮发酵品质的影响/div div本试验主要研究添加三种不同水平细胞壁降解酶对象草青贮30天发酵品质的影响。本试验设定10个处理：对照组，推荐水平纤维素酶组（50 mg kg-1<上标!>），5倍推荐水平纤维素酶组（250 mg kg-1<上标!>），10倍推荐水平纤维素酶组（500 mg kg-1<上标!>），推荐水平半纤维素酶组（20 mg kg-1<上标!>），5倍推荐水平半纤维素酶组（100 mg kg-1<上标!>），10倍推荐水平半纤维素酶组（200 mg kg-1<上标!>），推荐水平cornzyme酶组（0.22 ml kg-1<上标!>），5倍推荐水平cornzyme酶组（1.1 ml kg-1<上标!>），10倍推荐水平cornzyme酶组（2.2 ml kg-1<上标!>）。结果显示：与对照组相比，添加纤维素酶和cornzyme酶组的pH值、氨态氮/总氮值、总挥发性脂肪酸和纤维素含量显著（P<0.05）降低，乳酸/乙酸值、乳酸和水溶性碳水化合物含量，显著（P<0.05）提高，且添加水平越高，效果越显著，半纤维素酶组的所有指标与对照组差异不显著（P>0.05）。综上所述，添加cornzyme酶和纤维素酶水平越高，发酵效果越好，半纤维素酶组没有明显改善青贮发酵品质。/div div试验三  三种细胞壁降解酶对象草青贮发酵品质影响的比较研究/div div本试验主要研究添加三种细胞壁降解酶和贮藏时间（0.5，1，2，3，5，7，14和30天）对象草青贮发酵品质的影响。本试验设定四个处理：对照组，纤维素酶组（500 mg kg-1<上标!>），半纤维素酶组（200 mg kg-1<上标!>）和cornzyme酶组（2.2 ml kg-1<上标!>）。结果显示：在整个发酵过程中，对照组的pH值下降缓慢，乳酸产量低，发酵品质不好。青贮1天后，所有处理组的pH值显著（P<0.05）低于对照组，乳酸含量显著P<0.05高于对照组。添加纤维素酶和cornzyme酶组显著（P<0.05）降低了氨态氮/总氮值、总挥发性脂肪酸含量和纤维素含量，显著（P<0.05）提高了乳酸/乙酸值和水溶性碳水化合物含量，半纤维素酶组与对照组差异不显著（P>0.05）。综上所述，添加cornzyme酶和纤维素酶能够增加发酵底物，从而提高了发酵品质，添加半纤维素酶没有改善青贮发酵品质。/div div试验四  添加单糖对象草青贮发酵品质的影响/div div本试验主要研究添加不同单糖和贮藏时间（0.5，1，2，3，5，7，14和30天）对象草青贮发酵品质的影响。本试验设定3个处理：对照组，葡萄糖组（3% FW）和木糖组（3% FW）。结果显示：在整个青贮发酵过程中，对照组的pH值下降缓慢，乳酸产量低，发酵品质差；与对照组相比，添加葡萄糖和木糖显著（P<0.05）降低了pH值（低于4.20）和氨态氮/总氮值（低于100 g kg-1<上标!>），提高了乳酸和水溶性碳水化合物含量，但在青贮2天后木糖组的总挥发性脂肪酸含量显著（P<0.05）高于对照组。综上所述，添加葡萄糖和木糖能改善象草青贮发酵品质，其中添加葡萄糖效果更佳。/div div /div

divThere are four experiments in this study. Using napier grass as silage raw materials and through adding additives to observe the fermentation dynamics of napier grass silage. The additives are formic acid 2.2 ml kg-1<上标!>, 4.4 ml kg-1<上标!>, 6.6 ml kg-1<上标!> FW, cellulase 50 mg kg-1<上标!>, 250 mg kg-1<上标!>, 500 mg kg-1 <上标!>FW, hemicellulose 20 mg kg-1<上标!>, 100 mg kg-1<上标!>, 200 mg kg-1<上标!> FW, Cornzyme 0.22 ml kg-1<上标!>, 1.1 ml kg-1<上标!>, 2.2 ml kg-1<上标!> FW, glucose 3% FW and xylan 3% FW./div divExperiment Ⅰ: Effect of adding different leves of formic acid on fermentation quality of napier grass silage/div divThe aim of this experiment was to evaluate formic acid 2.2 ml kg-1<上标!>, 4.4 ml kg-1<上标!>, 6.6 ml kg-1<上标!> FW and storage time 0.5,1,2,3,5,7,14 and 30 days on fermentation quality of napier grass silage. The results were followed: Lactic acid content rapidly increased, pH value quickly lowered and NH3<下标!>-N content was lower than 60 g kg-1<上标!> TN, which indicated good fermentation quality of control group during ensiling 30 days. In 30 days ensiling process, compared with the control group, adding 2.2, 4.4 and 6.6 ml kg-1<上标!> formic acid slowed the declining rate of water soluble carbohydrates and the slowing effects of adding 4.4 and 6.6 ml kg-1<上标!> formic acid were better than adding 2.2 ml kg-1<上标!> P<0.05. After ensiling 3 days, NH3<下标!>-N and butyric acid content of adding 2.2 ml kg-1<上标!> formic acid silages rapidly increased and the contents of them were higher than control group, adding 4.4 and 6.6 ml kg-1<上标!> P<0.05. Adding 4.4 and 6.6 ml kg-1<上标!> formic acid prohibited silage to produce lactic, acetic, propionic and butyric acid, and made silages had lower NH3<下标!>-N <12 g kg-1<上标!>TN. In conclusion, after ensiling 30 days, without adding formic acid made napier grass silages had good fermentation quality while adding 2.2 ml kg-1<上标!> formic acid lowered the fermentation quality. Adding 4.4 and 6.6 ml kg-1<上标!> formic acid had the best effects on preserving napier grass./div divExperiment Ⅱ: Effect of adding cell wall-degrading enzymes at three different levels on fermentation quality of napier grass silage/div divThe aim of this experiment was to evaluate the affection of cell enzymes at three different levels on fermentation quality of napier grass silage on 30th day. The experiment setted ten treatments: control group, the recommended level of cellulase group 50 mg kg-1<上标!>, five times the recommended level of cellulase group 250 mg kg-1<上标!>, ten times the recommended level of cellulase group 500 mg kg-1<上标!>, The recommended level of hemicellulose group 20 mg kg-1<上标!>, five times the recommended level of hemicellulose group 100 mg kg-1<上标!>, ten times the recommended level of hemicellulose group 200 mg kg-1<上标!>, the recommended level of the cornzyme enzyme group 0.22 ml kg-1<上标!>, five times the recommended level of the cornzyme enzyme group 1.1 ml kg-1<上标!>, and ten times the recommended level of the cornzyme enzyme group 2.2 ml kg-1<上标!>. The results showed that: compared with the control group, pH value, NH3<下标!>-N/TN value, the total volatile fatty acids and cellulase contents of adding cellulase and cornzyme enzyme group to be significant P<0.05 lower, and lactic acid/acetic acid value, lactic acid and water soluble carbohydrate contents increased significantly P<0.05 , the higher adding, the effect was more significant, all the indicators of the hemicellulose group compared with the control group had no significant difference P>0.05. In summary, adding cornzyme and cellulase enzyme higher, the fermentation was better, the hemicellulose group had no significantiy improving on fermentation quality of napier grass silage./div divExperiment Ⅲ: Comparative study the effect of three kinds of cell wall degrading enzymes on fermentation quality of napier grass silage/div divThe aim of this experiment was to evaluate three kinds of cell wall degrading enzymes and storage time 0.5,1,2,3,5,7,14 and 30 days on fermentation quality of napier grass silage. The experiment setted four treatments: control group, the cellulase group 500 mg kg-1<上标!>, hemicellulose 200 mg kg-1<上标!> group and cornzyme enzyme group 2.2 ml kg-1<上标!>. The results showed that: in the fermentation process, pH value of the control group decreased slowly, low lactic acid production, fermentation quality was poor. After ensiling 1 day, pH values of all treatment groups reduced significantly P<0.05 lower than the control group, the lactic acid content was significant P<0.05 higher than the control group. Cellulase and cornzyme enzyme groups reduced significantly P<0.05 NH3<下标!>-N/TN value, the total volatile fatty acid and cellulase contents, and significantly P<0.05 increased LA/AA value and water soluble carbohydrates content. Compared with the control group, hemicellulose enzyme group had no different significant P>0.05. In summary, that addding cornzyme and cellulase can increase the fermentation substrate, resulting in improved fermentation quality of napier grass silage, adding hemicellulose had no improving fermentation quality of napier grass silage./div divExperiment Ⅳ: Effect of adding monosaccharide on fermentation characteristics of napier grass silage /div divThe aim of this experiment was to evaluate monosaccharide and storage time 0.5,1,2,3,5,7,14 and 30 days on fermentation quality of napier grass silage. This experiment setted three treatments: control group, glucose group 3% FW and xylose group 3% FW. The results showed that: in the silage fermentation process, the pH value of the control group decreased slowly, low lactic acid production, fermentation quality was poor. Compared with the control group, glucose and xylose groups had significantly P<0.05 lower pH value less than 4.20, NH3<下标!>-N/TN less than 100g kg-1<上标!> value, and improved the lactic acid production and saved more of water soluble carbohydrates content in the silage, but after ensiling 2 days, the total volatile fatty acids content of xylose group was significant P<0.05 higher than the control group. In summary, adding glucose and xylose can improve fermentation quality of napier grass silage, and glucose better./div div /div