紫花苜蓿和裸燕麦混贮发酵品质和营养成分分析

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(P0.01或P0.05),显著或极显著升高LA(乳酸)含量(P0.01或P0.05),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(P0.05或P0.01),对其他养分含量影响不大(P0.05)。混合比例对青贮饲料的所有发酵项目均有极显著影响(P0.01),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(P0.05或P0.01),对其他养分指标影响不显著(P0.05)。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。

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

Using sun-dried or fresh alfalfa and naked oats as materials, five silages, including alfalfa silage, naked 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), neutral detergent fiber (NDF) (P<0.05 or P<0.01), whereas had no effect on other nutrient indexes. In conclusion, 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 nutrient 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.