This study aimed to investigate the effect of supplementing Isochrysis galbana (I. galbana) at levels of 0 (control), 1, 2, 3, 4, and 5 (g/100 g DM) of the diet on the gas production kinetics, methane production, rumen fermentation parameters, and relative microbial population in vitro. Supplementation of I. galbana at high level (5 g/100 g DM) caused a significant decrease in total gas production (p < 0.05). High supplementation rates (4 and 5 g/100 g DM) decreased CH4 production relative to the control by 18.4% and 23.2%, respectively. Although rumen ammonia nitrogen (N‐NH3) and total volatile fatty acids (VFA) concentrations were affected by dietary treatments, but the VFA profile did not changed. The relative proportion of protozoa and methanogenic archaea as well as Anaerovibrio lipolytica, Prevotella spp., Ruminococcus flavefaciens, and Fibrobacter succinogenes were decreased significantly as a result of microalgae supplementation. However, the relative abundance of Ruminococcus albus, Butyrivibrio fibrisolvens and Selenomonas ruminantium were significantly increased (p < 0.05), related to the control group. As well, the pH was not affected by dietary treatments. It was concluded that I. galbana reduced in vitro CH4 production and methanogenic archaea that its worth to be investigated further in in vivo studies.

中文翻译：

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探讨补充不同水平的等鞭金藻对体外瘤胃发酵参数的影响

本研究旨在探讨补充的效果等鞭金藻（我。加尔巴纳）在饮食的 0（对照）、1、2、3、4 和 5 (g/100 g DM) 水平下对气体产生动力学、甲烷产生、瘤胃发酵参数和体外相对微生物种群的影响。补充我。加尔巴纳高水平（5克/100克干物质）导致总产气量显着下降（p< 0.05）。高补充率（4 和 5 g/100 g DM）可降低 CH4产量相对于对照分别提高了18.4%和23.2%。虽然瘤胃氨氮（N-NH3）和总挥发性脂肪酸 (VFA) 浓度受到饮食治疗的影响，但 VFA 谱没有改变。原生动物和产甲烷古菌的相对比例以及解脂厌氧弧菌,普雷沃特拉种，黄瘤胃球菌， 和产琥珀纤维杆菌由于补充微藻，显着减少。然而，相对丰度白色瘤胃球菌,溶纤维丁酸弧菌和反刍硒单胞菌均显着增加（p< 0.05)，与对照组相关。此外，pH 值也不受饮食治疗的影响。结论是我。加尔巴纳体外CH减少4产甲烷古菌值得在体内研究中进一步研究。