添加剂对青藏高原不同成熟期异燕麦青贮发酵特性的影响

Effects of Additives on Fermentation Quanlity of Helictotrichon virescens Henr at Different Maturity Stages on the Qinghai Tibetan Plateau

为有效利用青藏高原当地牧草资源解决冬季饲料短缺问题,对异燕麦(Helictotrichon virescens Henr.)的青贮发酵进行了研究。异燕麦在抽穗/开花期收获,在阳光充足的条件下萎蔫,切碎,在小袋筒仓中抽真空,在室温(5℃~15℃)下储存60d。青贮饲料在不使用(CK)或使用本地乳酸菌(LAB)接种剂(IN1)、商业乳酸菌接种剂(IN2)和苯甲酸钠(BL)的情况下进行处理。与开花期相比,抽穗期异燕麦对照青贮饲料中乳酸和乙酸含量较高(P<0.05),pH、丁酸和氨氮水平较低(P<0.05)。与对照相比,添加剂在青贮过程中通过抑制酵母菌、需氧菌和大肠菌群来提高(P<0.05)有氧稳定性。特别是,本地LAB接种剂增加了(P<0.05)青贮饲料中乳酸盐、乙酸盐和丙酸盐的浓度,并降低了丁酸盐和氨氮的浓度。本研究证实,本地乳酸菌接种剂可以提高异燕麦的青贮品质,异燕麦可能是青藏高原上牦牛等动物的潜在冬季饲料。

To effectively use local grass resources to cover the winter feed shortage on the Qinghai-Tibetan Plateau,the silage fermentation of perennial oat(Helictotrichon virescens Henr.)were investigated.Perennial oat was harvested at heading/flowering stage,wilted under sunny conditions,chopped,vacuumed in small bag silos and stored at ambient temperatures(5℃~15℃)for 60 days.The silages were treated without(CK)or with local lactic acid bacteria(LAB)inoculant(IN1),commercial LAB inoculant(IN2)and sodium benzoate(BL).Control silages of perennial oat at heading stage showed higher(P<0.05)lactate and acetate contents and lower(P<0.05)final pH,butyrate and ammonia contents than that at flowering stage.Compared with control,additives increased(P<0.05)aerobic stability by inhibiting yeasts,aerobic bacteria and coliform bacteria during ensiling.In particular,local LAB inoculant increased(P<0.05)concentrations of lactate,acetate and propionate,and decreased concentrations of butyrate and ammonia-N in silages.This study confirmed that local LAB inoculant could improve silage quality of perennial oat,and this could be a potential winter feed for animals such as yaks on the Qinghai Tibetan Plateau.