温度对垂穗披碱草青贮品质的影响

为探讨不同温度下青藏高原垂穗披碱草（Elymus nutans）贮藏过程中发酵品质的动态变化，本研究以采自青海省果洛藏族自治州的垂穗披碱草为青贮原料，在当地完成塑料袋青贮后带回实验室分别置于15和25 ℃下进行青贮，在贮藏2、4、6、8、12、14、30、60 d后开袋，测定其相关指标。结果表明，15 ℃处理下，pH值缓慢下降至5.68，乳酸含量1.44%，青贮效果不佳；25 ℃增加了乳酸含量（6.21%），使pH值显著降至4.27（P<0.05），取得了良好的青贮效果。随着贮藏时间的延长，AN/TN值逐渐增加，乙酸含量在发酵初期(4 d内)显著增加（P<0.05），在发酵后期水溶性碳水化合物含量显著降低（P<0.05），之后保持稳定。温度和发酵时间对粗蛋白、中性洗涤纤维和酸性洗涤纤维含量没有显著影响（P>0.05）。

Effects of temperature on fermentation quality of Qinghai Tibet Plateau Elymus nutans silage

Effects of temperature on dynamics of Qinghai Tibet plateau Elymus nutans fermentation quality in the process of ensiling was investigated. The material was derived from Guoluo Tibetan Autonomous Prefecture of Qinghai Province. Plastic bag silage was finished in local area and was put in 15 ℃and 25 ℃ in the laboratory. The bags of each treatment were opened 2, 4, 6, 8, 12, 14, 30 and 60 d after ensilage. The results showed that pH value decreased slowly to 5.68, the lactic acid content increased to 1.44% at 15 ℃, and the fermentation quality was ineffective. 25 ℃ lowered the pH value and increased lactic acid content significantly (P<0.05). The pH value was reduced to 4.27 and the lactic acid content was increased to 6.21%, which achieved good effects of silage. AN/TN value gradually increased with storage time, the acetic acid content increased significantly during the first 4 d (P<0.05). Water soluble carbohydrate content decreased at the end of the fermentation significantly (P<0.05) and remained stable. Temperature had no significant effect on the contents of crude protein, neutral detergent fiber and acid detergent fiber (P>0.05).