添加剂对紫花苜蓿和裸燕麦混合青贮品质的影响

为探讨添加剂及其不同混合比例对紫花苜蓿（Medicago sativa）和裸燕麦（Avena nuda）混贮饲料品质的影响，将二者按质量比1︰1，1︰2和2︰1进行混合青贮，3个添加剂处理，分别为1：2%蔗糖、0.0004%乳酸菌及2%蔗糖+0.0004%乳酸菌，青贮60 d后进行品质鉴定。结果显示，随裸燕麦混合比例提高，混贮饲料的pH值有所降低，乳酸含量显著增加（P<0.05），乙酸、丙酸、丁酸及总挥发性脂肪酸含量不同程度降低。苜蓿与裸燕麦混合比例为1∶2时，添加2%蔗糖或0.0004%乳酸菌均可降低非蛋白氮组分含量。其中，添加2%蔗糖+0.0004%乳酸菌处理的发酵品质最佳，但2种添加剂对混贮饲料纤维降解作用不明显。

Effect of Additives on Quality of Mixed Silages of Medicago Sativa and Avena nuda

The study was conducted to discuss the effects of additives and different mixing ratios on the quality of mixed silages of alfalfa (Medicago sativa) and naked oats (Avena nuda). Naked oats and alfalfa were used as the raw materials, mixed at mass ratios of 1:1, 2:1 and 1:2, respectively, to prepare mixed silages. Each mixed silage was divided into four groups:the control group (CK), the 2% sucrose (S) group, the 0.0004% lactobacillus (LD) group, and the 2% S+0.0004% LD group. The quality of each silage was evaluated after 60 d. The results showed that with increasing ratio of naked oats to alfalfa (N/A ratio), the pH of the mixed silages decreased to a certain extent, the content of lactic acid increased significantly (P<0.05), and the quantities of acetic acid, propionic acid, butyric acid and total volatile fatty acids decreased to different extents. In addition, both 2% S and 0.0004% LD added to the mixed ratio of 1:2 (A/N ratio) decreased the quantity of the non-protein nitrogen components. The silages treated with 2% S+ 0.0004% LD exhibited the optimal fermentation quality. However, neither LD nor S had a significant effect on the degradation of the fibre components of mixed silages.