This study was conducted to study the effects of ensiled alfalfa (Medicago sativa) and red clover (Trifolium pretense) at different ratios on dynamics of fermentation parameters, N distribution, protein fractions, and protease activities during ensiling. Alfalfa and red clover were harvested and wilted to 35 and 25% dry matter, respectively, chopped to 1 cm, mixed, weighed into 1.0-L buckets at a density of 700 g/L, and ensiled for 1, 3, 7, 15, and 30 d at 30°C. The treatments were mixing ratio of alfalfa to red clover at 100:0, 70:30, 50:50, 30:70, and 0:100 (R0, R30, R50, R70, and R100, respectively; fresh weight). For each ensiling duration, 3 replicates of each treatment were prepared. With increasing proportion of red clover in silage, total N content and proportions of nonprotein N, peptide N, free amino acid N, and NH₃-N decreased linearly, and PC (indigestible true protein, acid detergent insoluble N) proportion increased linearly after ensiling. Moreover, the final pH was lower in R50 and R100 than R0 (4.29, 4.20 vs. 4.48, respectively) on d 30. Also, lactic acid concentration on d 30 was higher in R50, R70, and R100 silage compared with R0 (7.77, 7.66, and 8.76 vs. 6.34, % of dry matter, respectively). The proportion of NH₃-N in R50 was lower than in R0 but closer to R100 after ensiling. During ensiling, proteases including carboxypeptidase, aminopeptidase, and acid proteinase activities decreased as red clover proportion increased. However, no differences were detected in aminopeptidase and acid proteinase activities among R50, R70, and R100 during ensiling. Overall, 50:50 was the optimal mixing ratio of alfalfa with red clover, showing good fermentation quality with lower pH and higher lactic acid concentration, reduced protease activities and proteolysis compared with pure alfalfa silage, and also more total N content than pure red clover silage.

本研究中，研究了青贮苜蓿（的效应紫花苜蓿）和红三叶草（红三叶青贮期间以不同的比例）上的发酵参数，N分配，蛋白级分，和蛋白酶活性动力学。收获苜蓿和红三叶草，分别枯萎至35％和25％的干物质，切成1厘米，混合，称重，以700 g / L的重量装入1.0升桶中，并青贮成1、3、7、15 ，并在30°C下放置30 d。处理为苜蓿与红三叶草的混合比为100：0、70：30、50：50、30：70和0：100（分别为R0，R30，R50，R70和R100；鲜重）。对于每个收尾持续时间，每种处理准备3次重复。随着红三叶草在青贮饲料中的比例增加，装满后，总氮含量和非蛋白质氮，肽氮，游离氨基酸N和NH ₃ -N的比例线性下降，PC（难消化的真蛋白质，酸性洗涤剂不溶性N）的比例线性上升。此外，R50和R100的最终pH值在d 30时低于R0（分别为4.29、4.20和4.48）。此外，R50，R70和R100青贮饲料中d 30的乳酸浓度高于R0（7.77）。分别为7.66和8.76与6.34％干物质的百分比）。NH ₃的比例包围后，R50中的-N低于R0，但更接近R100。在青贮过程中，随着三叶草比例的增加，包括羧肽酶，氨肽酶和酸性蛋白酶的蛋白酶活性降低。但是，在青贮过程中，R50，R70和R100之间的氨肽酶和酸性蛋白酶活性均未检测到差异。总的来说，苜蓿与红三叶草的最佳混合比例为50:50，与纯苜蓿青贮相比，发酵质量好，pH较低，乳酸浓度较高，蛋白酶活性和蛋白水解性降低，总氮含量也比纯红三叶草高青贮饲料。