不同品种牧草间组合时体外产气发酵特性研究

Combinative effects of different forage species on in vitro fermentation characteristics

采用体外发酵产气技术研究了鲁梅克斯杂交酸模-三叶草分别与皇竹草、桂牧1号、冬牧70、矮象草、牛鞭草、黑麦草和苏丹草按0∶100、25∶75、50∶50、75∶25和100∶0的比例进行组合时的体外发酵产气特性。结果表明,当鲁梅克斯-三叶草分别与皇竹、桂牧1号和冬牧70组合时,产气量和理论最大产气量以鲁梅克斯-三叶草占75%时最高,而与黑麦草组合时则以25%时最高,并显著(P<0.05)高于其占75%的组合。与矮象草和苏丹草组合时以其占50%时最高,而与牛鞭草组合时则以50%最低。当鲁梅克斯-三叶草与除黑麦草之外的牧草组合时,产气速率随鲁梅克斯-三叶草所占比例的上升而上升,与黑麦草组合时,产气速率则呈相反方向变化,但不同组合比例间无显著差异。当鲁梅克斯-三叶草与除皇竹、桂牧1号、牛鞭草和冬牧70以外的禾本科牧草组合时,不同比例的牧草组合不同发酵时间点之间的正组合效应达到了显著水平。结论认为,3种牧草间组合可不同程度地提高牧草的体外发酵产气量。

This study was conducted using in vitro gas production techniques in order to investigate the association effects of Rumex-- Trifolium forage mixed with different gramineous forages on gas production. The plants used in the mixtures were ： Pennisetunz purpureum X P. americanum, Guimu No. 1, Secale carele, Pennisetum purpureum cv. mott, Hemarthria japonica ,Lolium perenne and Sorghum sudanens. These mixtures were all replicated at ratios of 0 ： 100,25 ： 75,50 ： 50,75 ： 25 and 100 ： 0. The results showed that the values of gas production and the maximum gas production（A）were the highest for Rumex-Trifolium at 75% in mixtures with Pennisetum purpureum × P. americanum, Guimu No. 1 and Secale carele, and at 50% in mixtures with Pennisetum purpureum cv. mott or Sorghum sudanens. The values for maximum gas production were both the highest,and significantly higher （P〈0.05） than the ratio of 75% Ruznex-- Tri.folium and 25% Lolium perenne. The lowest value was for Rumex-Tri.folium mixed with Hemarthria copressa at a ratio of 50%. The trend of increased gas production occurred with increasing Rumex- Trifolium ratios in combination with forages,with the exception of Lolium perenne,which decreased with an increase in the Rumex--Trifolium ratio. However,the differences were not significant between the same plant combinations at different ratio proportions. Significant positive associative effects （P〈0.05） on gas production were produced consistently in mixtures with Rumex--Trifolium mixed with browses,with the exception of Pennisetum purpureum × P. americanum,Guimu No. 1, Hemarthria japonica and Secale carele ,at different proportions. It was concluded that the fermentation of pasture could be improved when three browse species were mixed.