【摘要】 本研究采用四因素三水平正交设计试验,探讨了玉米粉（A）（0、3%、6%）、尿素（B）（0、0.3%、0.6%）、乳酸菌（C）(0、5、10 g·t^-1)、密度（D）(700、800、900 kg·m^-3)对高水分杂交狼尾草（Pennisetum americanum×P. purpureum）青贮品质及营养价值的影响,筛选出最佳的青贮密度以及玉米粉、乳酸菌和尿素添加量,以提高杂交狼尾草的青贮品质。结果显示:1) 6个处理组感官评定综合评分9～15分,等级为二级以上。2)随着玉米粉剂量的增加,极显著地提高了青贮料粗蛋白（crude protein, CP）含量和相对饲用价值（relative feeding value, RFV）（P <0.01）,极显著地降低了中性洗涤纤维（neutral detergent fiber, NDF）、酸性洗涤纤维（acid detergent fiber, ADF）、粗灰分（crude ash, Ash）含量、pH以及氨态氮的水平（P <0.01）。3)尿素极显著地提高了青贮料中CP含量与RFV （P <0.01）,显著地降低了NDF和ADF含量（P <0.05）,当尿素的添加量为0.6%时,CP含量提高了7.05%,NDF和ADF含量分别降低了1.38%和1.45%。4)当乳酸菌剂添加量和青贮密度分别为5 g·t^-1和700 kg·m^-3时,RFV最高,NDF含量最低,干物质（dry matter, DM）含量介于其他处理之间。上述结果表明,3种添加物均能显著改善杂交狼尾草青贮发酵效果,其主次影响顺序分别为玉米粉>尿素>乳酸菌剂,且密度为700 kg·m^-3时效果最好。最优配比为6%的玉米粉、0.6%的尿素、5 g·t^-1的乳酸菌、700 kg·m^-3的密度。更多还原

【Abstract】 In order to improve the quality of hybrid Pennisetum silage, an orthogonal design was adopted in this study, with four factors at three levels, namely corn flour（A）（0, 3%, and 6%）, urea（B）（0, 0.3%, and 0.6%）, lactic acid bacteria（C）(0,5, and 10 g·t^-1), and density（D）(700, 800, and 900 kg·m^-3), to explore the effects of the four factors on quality and nutritional value of Pennisetum silage and to screen the optimum silage density and additive amount of corn meal, lactic acid bacteria, and urea. The results showed that: 1) The comprehensive scores of sensory assessment in the six treatment groups ranged from 9 to 15, with a grade 2 or above. 2) Corn flour significantly increased crude protein（CP） and relative feeding value（RFV）（P < 0.01） and significantly decreased neutral detergent fiber（NDF）, acid detergent fiber（ADF）, crude ash （Ash）, p H value, and ammonia nitrogen content in a dose-dependent manner（P < 0.01）. 3) Urea dose-dependently enhanced CP and RFV values（P < 0.01） but significantly reduced NDF and ADF content（P < 0.05）. When urea was added to 0.6%,CP increased by 7.05%, but NDF and ADF decreased by 1.38% and 1.45%, respectively. 4) When treated with lactic acid bacteria at 5 g·t^-1 and density at 700 kg·m^-3, respectively, the silage possessed the highest RFV but the lowest values of NDF and dry matter（DM） in the treatments. In conclusion, the three additives improve the fermentation effect of hybrid Pennisetum silage in the order of flour > urea > lactic acid bacteria, with the best effect at 700 kg·m^-3. The optimal combination includes 6% corn flour, 0.6% urea, 5 g·t^-1 lactic acid bacteria, and density of 700 kg·m^-3.更多还原