【作者】 师希雄；

【导师】 曹致中； 侯向阳；

【作者基本信息】 甘肃农业大学 ， 动物营养与饲料科学， 2005， 硕士

【摘要】 以苜蓿草渣为材料,采取单因子完全随机设计,分不同时间点(青贮后第5d、15d、25d、和35d)研究不同添加物,不同添加比例甲酸(1%,2%)、糖蜜(5%,10%)、丙酸(1%、2%)对草渣青贮品质的影响。再以这7 个处理的青贮料为材料作两级离体消化试验。结果表明:1)青贮以后苜蓿草渣的干物质消化率、有机物质消化率与原料相比都显著提高(p<0.01)。2)除对照组与5%糖蜜组35d 的的粗蛋白含量比青贮前显著降低外(p<0.05),其余各组的营养成分在整个青贮过程中差异不显著。3)苜蓿草渣中添加甲酸后,加速了酸化过程,pH 值降低,4 个时间点青贮料的pH 值都较对照极显著下降(p<0.01);蛋白分解酶以及腐败微生物对青贮料蛋白质的分解破坏作用受极大抑制;NH3-N 含量也较对照组极显著下降(p<0.01);低比例的甲酸促进乳酸生成,高比例的甲酸抑制青贮的自然发酵过程,乳酸的产量在4 个时间点的测定值受甲酸添加量的影响显著(p<0.01),呈下降趋势,VFA 产量降低。4)随着糖蜜添加比例的增加,青贮料的pH 值在四个时间点均显著低于对照(p<0.01);氨氮及酸性洗涤纤维含量都显著降低(p<0.01),乳酸产量显著增加(p<0.01),不利青贮发酵的微生物活动受抑制。5)丙酸的添加也加速了酸化过程,与对照组相比,四个时间点,青贮料的pH 值以及氨氮、乳酸的含量都显著降低(p<0.01)。. 综合评定各种添加剂对苜蓿草渣青贮品质的影响,这些处理青贮效果从好到差的顺序依次为.:1%甲酸组,2%甲酸组,1%丙酸组,2%丙酸组,10%糖蜜组,5%糖蜜组,对照组。更多还原

【Abstract】 The experiments selected dregs after extracting leaf protein from Medicago sativa of the second years as materials,and designed by randomized-single factor. The effects on the quality of the material at different ensiling time through adding different additives:formic acid at a rate of 1%、2%;molasses at a rate of 5%、10%;Third acid at a rate of 1%、2% were studied. The results showed :1)All treatments’DM digestibility and OM digestibility are higher than material(p<0.01). 2) The content of protein in the molasses of 5% group and the control group decreased significant(p<0.05). 3) On the four days ,formic acid addition declined the pH value ,compared with the control (p<0.01); the content of Ammonia nitrogen also decreased with the control (p<0.01). The low adding of formic acid advanced LAB,but high adding of formic acid prevented LAB growth .On four days ,the production of lactic acid declined significant (p<0.01), and the content of VFA also decreased compared with the control . 4) With the increasing of molasses adding ,on four days ,the pH value is lower than the control (p<0.01); the content of ammonia nitrogen and ADF also decreased significant (p<0.01); but the production of lactic acid increased compared with the control(p<0.01);the content of VFA also improved significant(p<0.01). 5) On the four days , Third acid addition declined the pH value , the content of ammonia nitrogen , lactic acid and VFA significant(p<0.01). 6) Analyze the effect by different additives synthetically, formic acid at a rate of 1% is the best one, following are formic acid at a rate of 2%, third acid at a rate of 1%, third acid at a rate cf 2%,molasses at a rate cf 10%,molasses at a rate of 5%,and control treatment.更多还原