不同添加剂和青贮密度对紫花苜蓿青贮品质的影响

摘要

本研究以第二茬初花期刈割的紫花苜蓿为原料,晾晒至干物质含量在60％左右,针对影响莒蓿青贮品质的添加剂和青贮密度两个因素,设计两因素试验,分别在600和650 kg·m-3青贮密度条件下添加植物乳杆菌(LP,Lactobacillus.plantarum)、乳酪乳杆菌(LC,Lactobacillus.casei)、蔗糖(S,sucrose)、纤维素酶(CE,acremonium cellulose)、LP+S、LC+S、LP+CE和LC+CE,以不添加作为对照.发酵45 d后进行开罐分析.结果表明,处理组S、S+ LP和S+ LC对于苜蓿青贮品质有一定的改善,这3个处理组的pH值、丁酸含量、NDF含量和ADF含量均低于对照组;添加CE、LP+CE和LC+CE对苜蓿青贮品质没有明显的改善;添加剂对苜蓿青贮品质有显著影响(P＜0.05),青贮密度对苜蓿青贮品质没有明显改善,但对干物质含量和氨态氮占总氮含量有显著影Ⅱ向(P＜0.05);两因素对苜蓿青贮品质的影响没有明显的交互作用(P＞0.05).%Medicago sativa (alfalfa) was used to make silage,with and without addition of additives.Alfalfa plants were freshly harvested at the initial blooming stage,when their dry matter content was about 400 g · kg-1 (fresh matter basis).The effects of additives and ensiling density on the quality of alfalfa silage were investigated in an experiment with eighteen treatment levels.The quality of silages was analyzed after 45 days of fermentation.The results showed that silage treated with S (sucrose),S+LP (sucrose+Lactobacillus.plantarum) and S+ LC (sucrose+Lactobacillus.casei) had lower pH,butyric acid content,NDF neutral detergent fiber content,and acid detergent fiber content than silages without these additives.Treatments with CE (acremonium cellulose),LP+CE,and LC+CE did not significantly improve the quality of silage.Treatments with additives resulted in higher quality alfalfa silage than treatments without additives (P＜0.05).Preparing silage with higher density did not significantly improve its quality but significantly increased its DM (dry matter) content and ammonia nitrogen/total nitrogen ratio (P＜0.05).The additive× density interaction was not a significant factor for silage quality (P＞0.05).