【作者】 孔凡德；

【导师】 刘建新； 吴跃明；

【作者基本信息】 浙江大学 ， 动物营养与饲料科学， 2002， 硕士

【摘要】 本研究以开发利用黑麦草饲料资源为目的，探讨了向黑麦草中添加麸皮、甜菜粕复合青贮的效果，研究了复合青贮对青贮料的发酵品质和营养价值的影响(试验1) ，探讨了凋萎青贮对青贮料发酵品质和营养价值的影响(试验2) 。试验1，研究了添加麸皮或甜菜粕高水分复合青贮黑麦草的效果。在黑麦草中添加麸皮或甜菜粕制作青贮料，即将试验分两大组：麸皮组和甜菜粕组，每组均按添加量的不同设四个处理，其中一个处理不添加麸皮或甜菜粕作为对照组，另三个作为试验组，分别添加麸皮或甜菜粕4％、8％、12％(以鲜重为基础)。每种添加水平设三个重复。青贮40天后，对各组青贮料发酵品质和营养价值进行评定。研究发现：添加麸皮和甜菜粕均可显著改善青贮料的发酵品质。麸皮处理组的NH3-N／TN比值分别降低38． 3％，47． 4％和45． 9％，差异极显著(p<O．01) ；pH值分别降低3． 2％，9． 9％和7． 1％，差异极显著(p<0． 01) 。 甜菜粕处理组的NH3-N／TN比值分别降低40． 8％，44． 4％和51． 5％，差异极显著(p<0． 01) ；pH值分别降低0． 69％，6． 4％和7． 3％，差异极显著(p<O．01) 。这说明，添加麸皮或甜菜粕可显著降低青贮料的pH值、抑制腐败菌对蛋白质的分解，降低NH3的生成。对干物质和粗蛋白回收率的分析显示：麸皮处理显著提高干物质的回收率，分别提高0． 7％，3． 5％和3． 9％(p<0． 05) ；粗蛋白的回收率分别提高2． 0％，4． 3％和4． 7％，差异显著(p<0． 05) 。甜菜粕处理组的干物质回收率分别提高6． 2％，5． 4％和6． 5％，差异极显著(p<0． 01) ；粗蛋白的回收率分别提高7． 1％，7． 1％和7． 8％，差异极显著(p<0． 01) 。这表明，添加麸皮或甜菜粕可防止养分损失，有效保存青贮料的营养成分。对青贮料有机酸含量的分析结果：各青贮处理提高了青贮料总有机酸的含量，显著降低丙酸含量(p<0． 01) 和丁酸含量(p<0． 01) ，其中添加8％、12％的麸皮或甜菜粕组均无丁酸发酵。麸皮处理组的乳酸含量分别提高76． 5％，140． 8％和119． 7％，差异极显著(p<0． 01) ，而甜菜粕组分别提高0． 9％，44． 7％和60． 2％，差异显著 浙江大学硕士学位论文 b①．05入说明添加鼓皮或甜菜粕能够显著促进乳酸发酵并抑制丁酸生成。 对营养价值的评定结果：各青贮处理显著提高了蛋白质的消化率，鼓皮处理组 分另提高 74％，76％和 770（P＜0．01），甜菜粕处理组分别提高 52．7％，56．l0和 74％ （P＜0．01）。甜菜粕处理对青贮料的消化能和干物质的体外发酵率无显著影响 （P）0．05）。添加鼓皮可显著提高青贮料的消化能（P＜0．of），分别提高11．4％、26．6％ 和 34．2％，但鼓皮处理对青贮料干物质的体外发酵率无显著影响（P＞0．05）。 试验2研究了凋萎青贮的效果。试验按不同的凋萎程度设3个处理，干物质含 量分别为 11．8％（对照组）、15．4o和 32．5％，每个处理设3个重复。青贮40天后， 对各组青贮料发酵品质和营养价值进行评定。 分析结果发现：凋萎处理可有效减少底部积水，显著提高干物质的回收率 …＜0．01），分别提高二．＊％和6．8％；显著降低 ＊＊N／TN＊值，分别降低12．＊％和 19．4％，差异极显著…功刀1＊ 对乳酸、乙酸和总有机酸含量及PH值无显著影响 （叩刀5），但显著抑制丙酸和丁酸发酵…叱刀1卜对营养价值的评定结果：凋萎处理 对青贮料的消化能和干物质的体外发酵率无显著影响O＞0刀5X 但可显著提高青贮 料的蛋白质消化率，分别提高 32．6％和 42．3％，差异极显著中、0刀1人 综上所述，黑麦草高水分单一青贮得不到优质青贮料，添加款皮或甜菜粕均可 减少青贮损失，明显改善黑麦草青贮品质和营养价值，添加水平越高，效果越好。 凋萎青贮可显著减少底部积水，明显改善黑麦草青贮品质和营养价值，其中，干物 质含量凋萎至32．5％组的效果最佳。更多还原

【Abstract】 Two experiments were carried out to investigate the effects of adding wheat bran(WB) or beet pulp(BP) on fermentation and nutritive value of silages from high moisture ryegrass(Expt. 1),and to study the effects of wilting on silage fermentation and nutritive value(Expt.2).In Expt.l,high moisture ryegrass was ensiled with WB or BP at four adding levels:0,40,80 and 120g/kg(fresh basis),respectively. All above silages were prepared triplicate in laboratory scale silos and opened 40 days after ensilage. The fermentation characteristics were evaluated by subjective quality,chemical composition,organic acids and pH value. The digestibility of energy and protein of ryegrass silage were predicted in vitro.Addition of WB or BP improved the fermentation characteristics and nutritive value of ryegrass silages. Compared to the control,the ratio of ammonia nitrogen to the total (NH3-N/TN) was decreased by 38.3,47.4 and 45.9%(p<0.01),the pH value was decreased by 3.2,9.9 and 7.1%(p<0.01),when ryegrass was added at levels of 4,8 and 12% WB. In BP added silages,the (NH3-N/TN) value was 40.8,44.4 and 51.5%(p<0.01) lower,the pH value was 0.69,6.4 and 7.3%(p<0.01) lower in groups 1,2 and 3 than those in control,respectively.The dry matter recovery(DMR) was 0.7,3.5 and 3.9%(p<0.05) higher,and the crude protein recovery(CPR) was 2.0,4.3 and 4.7%(p<0.05) higher for the WB-added silages than the control. Compared to the control,the DMR was increased by 6.2,5.4 and6.5%(p<0.01) and the CPR was increased by 7.1,7.1 and 7.8%(p<0.01) for the BP-added silage.Addition of WB or BP increased total organic acid content of silages,significantly decreased the content of propionic acid (p<0.01) and butyric acid (p<0.01). There were no butyric acids found in the silages added with higher levels of WB or BP. The lactic acid content was 76.5,140.8 and 119.7%(p<0.01) higher in WB-added groups than that in control. Compared to the control,the lactic acid content was increased by 0.9,44.7 and 60.2%(p<0.05) in BP-added groups. However there were little differences in acetate content between the groups treated with WB or BP.The in vitro crude protein digestibility (IVCPD) were all significantly higher in WB or BP-added groups than that in the control. The IVCPD in WB-added silage was 74. 76 and 77%(p<0.01) higher than that in the control. Addition of BP significantly increased the IVCPD,which was 52.7,56.1 and 74%(p<0.01) higher than the control group,respectively. The digestible energy (DE) and DM fermentation ratio (DMFR) showed no significant differences in BP-added silages. However the DE was 11.4,26.6 and 34.2%(p<0.01) higher for the WB-added silages than the control.In Expt.2,the effects of wilting prior to ensiling on fermentation characteristics and nutritive value were studied. The DM content of ryegrass was increased by wilting from 118g/kg (control) to 154 and 325g/kg,respectively. All above materials were prepared triplicate in laboratory scale silos and opened 40 days after ensilage. Wilting generally decreased water at bottom of silos,implying less effluent on farm from silo. Compared to the control,the DMR was 2.9 and 6.8%(p<0.01) higher,and the NH3-N/TN value was 12.2 and 19.4%(p<0.01) lower for the wilted silages,respectively. The pH and contents of lactic,acetic and total acids showed no significant differences between the groups (p>0.05). The contents of propionic and butyric acid were significantly decreased(p<0.01). The DE and DMFR also showed no significant differences between the groups,while wilting significantly increased the IVCPD value,which was increased by 32.6 and 42.3%(p<0.01),respectively.In summary,it is difficult to ensile fresh ryegrass successfully without any additive. Addition of WB or BP may reduce dry matter losses during ensilage,andimprove both the fermentation quality and nutritional value of ryegrass silages. The more the adding level of WB or BP,the better the effect on the fermentation quality of ryegrass silages. The optimal level at which wheat bran or beet pulp is added will de更多还原