密度对玉米青贮发酵品质、微生物和有氧稳定性的影响

Effect of Density on Fermentation Quality,Microbial Quantity and Aerobic Stability of Corn Silage

以新饲玉10号青贮玉米为材料,发酵装料密度设5个梯度(350kg/m^3、400kg/m^3、500kg/m^3、600kg/m^3、700kg/m^3),以50d为发酵期,检测发酵期间各密度处理第1d、3d、5d、7d、9d、15d、30d、50d青贮发酵品质、主要微生物以及有氧稳定性的变化。结果表明,发酵时间与密度的交互作用对pH值、乳酸、乙酸和氨态氮含量以及霉菌数量影响极显著(P<0.01)。增加青贮密度可有效提高青贮品质,改善发酵特性。发酵50d后,密度为600kg/m^3青贮饲料的乳酸菌数量最多,达9.19lg cfu/gFW,pH值最低,为3.97,且有氧稳定性显著高于其他处理(P<0.05),达100h。综合评价表明,青贮密度700kg/m^3的全株玉米青贮综合评分最高。

Corn（cv.Xinsiyu 10）was ensiled at five bulk densities（350,400,500,600 and 700 kg/m^3）.Silage samples were collected after fermentation for 1,3,5,7,9,15,30,and 50 days.After the silos were opened,the silage was analyzed to determine fermentation quality,microbial quantity as well as the aerobic stability.The fermentation quality of the silage increased as bulk density increased.The results indicated that the effects of interaction of fermentation time and density on pH value,lactic acid,acetic acid,NH3-N content and mold quantity of corn silage were significant（P〈0.05）.After 50 days of fermentation,corn silage of treatment 600 kg/m^3 had the highest lactic acid bacteria quantity,up to 9.19 lg cfu/g FW,while pH value was the lowest,3.97.The stable time after exposure to oxygen of treatment 600 kg/m^3 was significantly higher than other treatments（P〈0.05）,reaching 100 h.Through comprehensive evaluation,the silage density of 700 kg/m^3 whole plant corn silage score was the highest.Therefore,nutritive values increased and fermentation characteristics improved as silage density increased.