紫花苜蓿和裸燕麦混贮发酵品质和营养成分分析

Quality of mixed naked oats(Avena nuda)and alfalfa(Medicago sativa)silage

以新鲜及晾晒后的紫花苜蓿和裸燕麦为原料,分别设计紫花苜蓿单贮、裸燕麦单贮、裸燕麦∶紫花苜蓿=1∶1、裸燕麦∶紫花苜蓿=2∶1及裸燕麦∶紫花苜蓿=1∶2混贮等5个处理,青贮60d后,对其感官评分、发酵品质和营养成分等进行分析。结果表明,鲜贮苜蓿在感官评定、V-Score及Kaiser评价体系中表现一般,而晾晒及混合青贮各处理组均能不同程度提高青贮评分。晾晒和混合青贮对发酵品质产生影响,两者显著或极显著降低pH值、PA(丙酸)、AA(乙酸)、BA(丁酸)和AN/TN(氨态氮/总氮)含量(P<0.01或P<0.05),显著或极显著升高LA(乳酸)含量(P<0.01或P<0.05),其中以裸燕麦∶紫花苜蓿=2∶1降低或升高最明显。晾晒对青贮饲料的干物质、可溶性碳水化合物及粗灰分含量具有显著或极显著影响(P<0.05或P<0.01),对其他养分含量影响不大(P>0.05)。混合比例对青贮饲料的所有发酵项目均有极显著影响(P<0.01),对粗蛋白质、可溶性碳水化合物及中性洗涤纤维含量具有显著或极显著影响(P<0.05或P<0.01),对其他养分指标影响不显著(P>0.05)。晾晒和混合青贮的交互作用可显著提高青贮饲料的发酵品质,但对养分含量影响不明显。因此,从青贮后感官评价、发酵品质及养分含量来看,紫花苜蓿和裸燕麦混合青贮品质优于单独青贮,且晾晒相对于鲜贮更易于青贮,而无论晾晒和鲜贮,当裸燕麦∶紫花苜蓿=2∶1时,青贮品质均优于其他各组。

Using sun-dried or fresh alfalfa and naked oats as materials,five silages,including alfalfa silage,na-ked oats silage,three mix silage,（alfalfa∶naked oats =1∶1,alfalfa∶naked oats =1 ∶2 and alfalfa∶naked oats =2 ∶1 ）,were prepared.After 60 days ensiling,the sensory score,fermentation quality and nutrition composition of silages were evaluated.The results revealed that silage made of fresh alfalfa showed a common performance in the sensory score and V-Score and Kaiser-Score evaluation system,while both silage made of sun-dried materials and mixed silage had a improved silage score.Sun-drying and mixing process had effect on silage quality,such as decreasing pH value,acetic acid （AA）,propionic acid （PA）,butyrate acid （BA）and ammonia nitrogen/total nitrogen （AN/TN）（P 〈0.01 or P 〈0.05）content of silages,significantly increasing lactate （LA）content （P 〈0.01or P 〈0.05）of silages.Among which,mixed silage of alfalfa and naked oats with a ratio of 2∶1 showed a biggest increasing and decreasing describe above.The sun-drying process had a significantly effect on the dry matter （DM）,water-soluble carbohydrate （WSC）and crude ash （Ash）content of silage,while had no effect on remaining nutrients.Notably,mixing process had significant effects on most of fermentative indexes,such as the content of crude protein （CP）,water-soluble carbohydrate （WSC）,neu-tral detergent fiber （NDF）（P 〈0.05 or P 〈0.01）,whereas had no effect on other nutrient indexes.In conclu-sion,the interaction of sun-drying process to silage materials and mixed ratio can improve silage quality,while had no effect on nutrient composition of silages.According to the sensory score,fermentation quality,and nu-trient content,the mixed and sun-dried materials can produce better silages than sole and fresh material,and silage made of naked oats and alfalfa with a ration of 2∶1 was the best.