添加玉米秸秆对甜菜渣青贮品质和体外消化率的影响

以甜菜渣和玉米秸秆为青贮原料,按照不同质量比(鲜样)混合青贮,分析添加玉米秸秆对甜菜渣青贮饲料化学成分、发酵品质和体外消化率的影响。结果表明:甜菜渣直接青贮其乳酸含量较低(0.67%),乙酸含量较高,为乙酸发酵类型;添加玉米秸秆显著降低了青贮饲料的pH(P0.05),显著提高了青贮饲料的乳酸含量(P0.05),9∶1和8∶2处理组显著降低了氨态氮的生成量(P0.05),其发酵类型均为乳酸发酵型。通过flieg评分体系对不同组合进行评价,其等级均为良好。添加玉米秸秆后除9∶1处理组以外,其他处理均显著降低了青贮饲料粗蛋白含量,提高了中性洗涤纤维和酸性洗涤纤维含量,表明添加玉米秸秆降低了青贮饲料的营养成分;添加玉米秸秆后其体外干物质消化率均显著低于ck(P0.05),除9∶1处理组以外其体外中性洗涤纤维、酸性洗涤纤维和粗蛋白消化率均显著低于ck(P0.05)。综合各项指标,认为甜菜渣和玉米秸秆的最佳混合青贮比例为90%甜菜渣+10%玉米秸秆(9∶1)。

Effects of Mixing Corn Straw into Beet Residue Silage on Silage Quality and in Vitro Digestibility

The beet residue and corn straw were the silage material,according to the weight proportion (fresh weight basis),the beet residue was mixed well with corn straw and the proportion was 100%(beet residue,ck);90%(beet residue)∶10%(corn straw);80%(beet residue)∶20%(corn straw);70%(beet residue)∶30%(corn straw);60%(beet residue)∶40%(corn straw);50%(beet residue)∶50%(corn straw),triplicate laboratory silos for all treatments were kept for 90 days then samples were taken for the analysis of silages for chemical composition,fermentation quality and in vitro digesitibility.The result showed that beet residue directly ensiling had low lactic acid content (0.67)and high acetic acid content,and the acetic acid dominated in total acid,the ensiling process may be acetic acid fermentation.Mixed corn straw could decrease pH value and increase the content of lactic acid(P<0.05),the treatments of T1 (9∶1)and T2(8∶2) decreased the NH3-N content(P<0.05),the ensiling process may be lactic acid fermentation and the flieg evaluation was good;Apart from T1(9∶1),the treatments of adding corn straw could decrease the crude protein content(P<0.05),increase NDF and ADF content(P<0.05),indicating the reduction of the nutrition of silage by adding corn straw.The IVDMD was lower than ck by adding corn straw,and apart from T1(9∶1),the IVNDFD,IVADFD and IVCPD had lower than ck by adding corn straw.It was concluded that 90%(beet residue)∶10%(corn straw) was the best proportion.