葡萄籽精油对体外瘤胃发酵和甲烷生成的影响

Effects of grape seed oil addition on rumen fermentation and methanogenesis in vitro

通过体外培养法研究发酵底物精粗比7∶3条件下,添加100,150和250μL/L葡萄籽精油对瘤胃发酵和甲烷产量的影响。采用气相色谱仪测定甲烷产量,培养24 h后,测定挥发性脂肪酸、pH、氨态氮浓度和原虫数。结果发现,添加葡萄籽精油100μL/L和150μL/L与对照组相比提高累计产气量、发酵液pH值(P<0.05)、乙酸摩尔比例,降低甲烷浓度(P<0.01)、丙酸、丁酸、戊酸和支链挥发性脂肪酸摩尔比例。葡萄籽精油添加量为150μL/L降低氨态氮浓度及瘤胃原虫数,添加100μL/L葡萄籽精油提高总挥发性脂肪酸。试验表明,适宜添加量的葡萄籽精油可以改变瘤胃发酵模式,增加丙酸乙酸比例,抑制甲烷生成。

A diet of 7 concentrate ： 3 forage was used as substrate in vitro, treatments were consisted of control group （0） versus three levels of grape essential oils （ 100, 150,250 μL/L）, 3 repeats in each group. In vitro gas production （GP） was recorded and methane production was determined 3, 6, 9, 12 and 24 h after incubation. Ammonia nitrogen, volatile fatty acids （VFAs） , protozoa and pH were measured after 24 h incubation. The resuhs showed that the gas production, pH and acetate proportion were increased by supplementations of 100 and 150 μL/L grape seed oils （P〈0. 05）, where the methane production （P〈0. 01 ）, molar proportion of propionate, butyrate, valerate and BCVFA decreased. In addition, ammonia nitrogen and protozoa were decreased by supplementation of 150μL/L grape seed oils, while, total volatile fatty acid increased by 100μL/L grape seed oils. In conclusion, addition of grape seed oils at a proper level could change the fermentation pattern, increase the propionate acetate ratio and inhibit methanogenesis.