Du Zhumei, Risu Na, Gentu Ge, Jia Yushan, Cai Yimin
Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization of Ministry of Agriculture, Key Laboratory of Grassland Resources, Ministry of Education, P. R. of China, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010019, China.
The Center of Ecology and Agrometeorology of Inner Mongolia, Hohhot 010019, China.
Asian-Australas J Anim Sci. 2020 Apr;33(4):556-567. doi: 10.5713/ajas.19.0212. Epub 2019 Aug 3.
To improve the utility of native grass resources as feed in China, we investigated the dynamics of protein and carbohydrate fractions among Inner Mongolian native grasses, during ensiling and the aerobic stage, using the Cornell Net Carbohydrate and Protein System.
Silages were prepared without or with lactic acid bacteria (LAB) inoculant. We analyzed the protein and carbohydrate fractions and fermentation quality of silages at 0, 5, 15, 20, 30, and 60 d of ensiling, and the stability at 0.5, 2, 5, and 10 d during the aerobic stage.
Inner Mongolian native grass contained 10.8% crude protein (CP) and 3.6% water-soluble carbohydrates (WSC) on a dry matter basis. During ensiling, pH and CP and WSC content decreased (p<0.05), whereas lactic acid and ammonia nitrogen (N) content increased (p<0.05). Non-protein N (PA) content increased significantly, whereas rapidly degraded true protein (PB1), intermediately degraded true protein (PB2), total carbohydrate (CHO), sugars (CA), starch (CB1), and degradable cell wall carbohydrate (CB2) content decreased during ensiling (p<0.05). At 30 d of ensiling, control and LAB-treated silages were well preserved and had lower pH (<4.2) and ammonia-N content (<0.4 g/kg of fresh matter [FM]) and higher lactic acid content (>1.0% of FM). During the aerobic stage, CP, extract ether, WSC, lactic acid, acetic acid, PB1, PB2, true protein degraded slowly (PB3), CHO, CA, CB1, and CB2 content decreased significantly in all silages, whereas pH, ammonia-N, PA, and bound true protein (PC) content increased significantly.
Control and LAB-treated silages produced similar results in terms of fermentation quality, aerobic stability, and protein and carbohydrate fractions. Inner Mongolian native grass produced good silage, nutrients were preserved during ensiling and protein and carbohydrate losses largely occurred during the aerobic stage.
为提高中国本土牧草资源作为饲料的利用率，我们运用康奈尔净碳水化合物和蛋白质体系，研究了内蒙古本土牧草在青贮和有氧阶段蛋白质和碳水化合物组分的动态变化。
制备了未添加或添加乳酸菌（LAB）接种剂的青贮饲料。我们分析了青贮0、5、15、20、30和60天时青贮饲料的蛋白质和碳水化合物组分以及发酵品质，以及有氧阶段0.5、2、5和10天时的稳定性。
内蒙古本土牧草干物质基础上粗蛋白（CP）含量为10.8%，水溶性碳水化合物（WSC）含量为3.6%。青贮期间，pH值以及CP和WSC含量降低（p<0.05），而乳酸和氨态氮（N）含量增加（p<0.05）。非蛋白氮（PA）含量显著增加，而快速降解真蛋白（PB1）、中度降解真蛋白（PB2）、总碳水化合物（CHO）、糖（CA）、淀粉（CB1）和可降解细胞壁碳水化合物（CB2）含量在青贮期间降低（p<0.05）。青贮30天时，对照和LAB处理的青贮饲料保存良好，pH值较低（<4.2），氨态氮含量较低（<0.4 g/kg鲜物质[FM]），乳酸含量较高（>1.0% FM）。在有氧阶段，所有青贮饲料中的CP、乙醚提取物、WSC、乳酸、乙酸、PB1、PB2、缓慢降解真蛋白（PB3）、CHO、CA、CB1和CB2含量均显著降低，而pH值、氨态氮、PA和结合真蛋白（PC）含量显著增加。
对照和LAB处理的青贮饲料在发酵品质、有氧稳定性以及蛋白质和碳水化合物组分方面产生了相似的结果。内蒙古本土牧草制成的青贮饲料质量良好，青贮期间养分得以保存，蛋白质和碳水化合物损失主要发生在有氧阶段。
