不同添加剂量的3-硝基酯-1-丙醇对体外瘤胃发酵参数及细菌多样性的影响

Effects of 3-NOP on Rumen Fermentation Characteristics and Bacterium Diversity by In Vitro Fermentation

通过体外瘤胃发酵法研究高精饲粮中添加不同剂量3-硝基酯-1-丙醇(3-NOP)对瘤胃发酵参数及细菌区系的影响,以期为3-NOP在我国反刍家畜生产方面提供理论依据和参考。试验采用单因素完全随机设计,设4个3-NOP添加剂量,即以干物质为基础向每克发酵底物中分别添加0 mg(对照组,C)、0.4 mg(低剂量组,LD)、0.8 mg(中剂量组,MD)和1.2 mg(高剂量组,HD)的3-NOP,体外发酵培养24 h。结果表明:与对照组相比,添加中高剂量的3-NOP显著降低了体外瘤胃发酵乙酸和丁酸生成量(P<0.05),但3个添加剂量的3-NOP均显著增加了丙酸生成量(P<0.05),显著降低了乙酸/丙酸值(P<0.05)。并且3-NOP处理组显著提高了普雷沃氏菌属(Prevotella 1)的丰度(P<0.05),却显著降低了瘤胃球菌属(Ruminococcaceae NK4A214group)的丰度(P<0.05)。其中普雷沃氏菌属(Prevotella 1)与丙酸含量呈显著正相关,但与乙酸含量呈显著负相关(P<0.05)。由此可见,在体外培养条件下,日粮中添加3-NOP能够调节菌群结构,显著影响了普雷沃氏菌属(Prevotella 1)和瘤胃球菌属(Ruminococcaceae NK4A214 group)的相对丰度,明显改变了乙酸和丙酸的生成比例,此试验条件下,日粮中添加中等剂量的3-NOP较为适宜。

This experiment aimed to investigate the effects of different doses of 3-nitrooxypropanol(3-NOP)added to high-concentrate feed on rumen fermentation parameters and bacterial community using an in vitro rumen fermentation method.The experiment employed a completely randomized design with four treatment groups:0(control group),0.4,0.8,and 1.2 mg of 3-NOP added into the fermentation substrates.The in vitro fermentation was conducted for 24 hours.The results of the experiment showed that compared to the control group,the medium and high doses of 3-NOP significantly reduced the production of acetic acid and butyric acid(P<0.05).However,all three doses of 3-NOP significantly increased the production of propionic acid(P<0.05),resulting in a significant decrease in the acetic acid to propionic acid ratio(P<0.05).Furthermore,the 3-NOP treatment groups significantly increased the relative abundance of Prevotella 1(P<0.05),while significantly decreasing the relative abundance of Ruminococcaceae NK4A214 group(P<0.05).Prevotella 1 showed a significant positive correlation with propionic acid content but a significant negative correlation with acetic acid content(P<0.05).These findings indicate that the addition of 3-NOP to the diet altered the in vitro rumen fermentation pattern,significantly changed the proportions of volatile fatty acids,and further altered the bacterial community structure.