添加亚麻酸及植物油对体外瘤胃发酵和甲烷生成的影响

利用瘤胃模拟体外产气法研究在高精料底物条件下添加富含十八碳不饱和脂肪酸的植物油和亚麻酸对瘤胃发酵和甲烷生成的影响。在植物油的筛选试验中,菜籽油、豆油和亚麻油分别添加底物干物质的10%,观察其对甲烷生成和发酵产物的影响。结果表明,豆油和亚麻油显著降低了产气量和甲烷产量,但甲烷产量的下降幅度更大,菜籽油无效果。同时,豆油和亚麻油显著升高了总挥发性脂肪酸含量和丙酸比例。选取筛选出的效果最显著的植物油——亚麻油,和亚麻酸一起比较研究其对瘤胃发酵的剂量效应,亚麻油和亚麻酸分别添加底物干物质的0%、3%、5%、7%和9%。亚麻油和亚麻酸分别在添加量为5%和3%时显著降低了甲烷产量,且抑制效果随添加剂量的提高而增强。亚麻油和亚麻酸显著改变瘤胃发酵模式向丙酸型发酵转变。这些结果表明,一些富含十八碳不饱和脂肪酸的植物油和亚麻酸可以在高精料日粮条件下改善瘤胃发酵,降低甲烷生成,且植物油抑制甲烷生成的效果与添加剂量和所含脂肪酸的不饱和度有关。

Effects of Supplemental Linolenic Acid or Vegetable Oils on in vitro Rumen Fermentation and Methane Emission

A series of in vitro studies were performed to evaluate the effects of unsaturated C18 fatty acid-rich oils and linolenic acid on rumen fermentation and methanogenesis with a high-grain substrate.In oil screening experiment,rapeseed oil,soybean oil and linseed oil were used as tested additives.Rumen fluid from sheep was incubated with ground corn with or without oil supplementation (10% of substrate DM) for 24 h to monitor rumen products.Gas production and methane emission decreased with addition of unsatur...