添加剂对饲料型四倍体刺槐青贮发酵品质和体外消化率的影响

[目的]探讨葡萄糖、糖蜜和乳酸菌对饲料型四倍体刺槐青贮发酵品质及体外消化率的改善效果。[方法]试验设对照组（C）、葡萄糖组（G）、糖蜜组（M）、乳酸菌组（L）、乳酸菌+葡萄糖组（L+G）、乳酸菌+糖蜜组（L+M），分别在青贮后7、14、30、60 d开窖取样，分析青贮饲料发酵品质和体外消化率。[结果]饲料型四倍体刺槐在整个青贮过程中乳酸产生和pH下降缓慢，致使青贮结束时，各组具有较低的乳酸（3.32~18.39 g？；kg-1）与较高的pH值（4.88~5.66），但各组仅检测到极微量的丁酸（小于 2 g？；kg-1）及较低的氨态氮/总氮值（54.52~60.54 g？；kg-1）。与对照组相比，G、M和L组未明显提高青贮饲料发酵品质和体外消化率，而L+G和L+M组有较明显的改善效果，其中L+M组在整个发酵过程中保持最高的乳酸含量和体外消化率。各处理组氨态氮/总氮值、粗蛋白含量与对照组相比无显著差异（P>0.05）；但各处理组中性洗涤纤维和酸性洗涤纤维含量均显著低于对照组（P<0.05），其中L+M组中性和酸性洗涤纤维含量最低（P<0.05）。[结论]添加葡萄糖、糖蜜和乳酸菌对青贮发酵品质和体外消化率有一定的改善效果，组合添加优于单独添加，其中L+M组改善效果最佳。
[Objectives]The objective of this study was to investigate the effect of additives on the fermentation quality and in vitro digestibility of tetraploid black locust(Robinia pseudoacacia L.). [Methods]The treatments were as follows:control group(no additives,C),glucose group(G),molasses group(M),inoculant(Lactobacillus plantarum) group(L),inoculant+glucose group(L+G),inoculant+molasses group(L+M). The silos were opened and sampled on 7,14,30 and 60 days after ensiling,respectively,and then the fermentation quality and in vitro digestibility of silages were analyzed. [Results]A slow accumulation of lactic acid and decline of pH were observed in tetraploid black locust silage,resulting in low lactic acid content(3.32-18.39 g？kg-1),high pH value(4.88-5.66),minor propionic acid and butyric acid(<2 g？kg-1)and low ammonia nitrogen/total nitrogen value(54.52-60.54 g？kg-1)at the end of ensiling. Compared with the control,G,M and L showed no great improvement on fermentation quality and in vitro digestibility,while L+G and L+M silages did. And the lactic acid content and in vitro digestibility value of L+M silage maintained the highest value during the fermentation process. There were no significant differences(P>0.05)in crude protein content among all treatments as compared with control. However,the neutral detergent fiber and acid detergent fiber contents were significantly lower than those of control(P<0.05),and L+M silage had the lowest neutral detergent fiber and acid detergent fiber content(P<0.05). [Conclusions]It was suggested that all additives improved the fermentation quality and in vitro digestibility of tetraploid black locust silage to some degree,and the combination treatment was superior to the single treatment. L+M silage performed best