添加剂对全混合日粮发酵品质和有氧稳定性的影响

Fermentation quality and aerobic stability of total mixed ration with additives

该试验研究了添加双乙酸钠和绿汁发酵液对含水稻秸秆、四棱豆藤、甜茶渣和精料的全混合日粮(total mixed ration,TMR)发酵品质和有氧稳定性的影响。实验分为4组:对照组(C,无添加)、双乙酸钠组(S,0.5%鲜重)、绿汁发酵液组(L,2.0 mL/kg鲜重)、双乙酸钠+绿汁发酵液组(SL,0.5%+2.0 mL/kg鲜重)。TMR在25℃厌氧条件下发酵35 d,4组TMR pH值、氨态氮含量均较低,丁酸含量低(0.42~0.49 g/kg干重),均具有良好的发酵品质,对照组、S组和SL组的乳酸含量及乳酸菌数量无显著性差异(P>0.05),添加双乙酸钠对乳酸菌发酵可溶性糖产生乳酸的过程没有影响,L组的乳酸含量最高(P<0.05),表明接种绿汁发酵液可促进乳酸发酵。在有氧稳定性方面,S组(>312 h)和SL组(>302 h)显著高于C组(>160 h)和L组(>130 h)(P<0.05)。此外,单独添加双乙酸钠或与绿汁发酵液组合添加在有氧暴露12 d后,pH值保持在4.50左右,乙酸含量处于较高水平,延长了有氧稳定性。结果表明,添加0.5%双乙酸钠可在不影响发酵品质的前提下提高发酵TMR的有氧稳定性,建议推广应用。

This study was carried out to assess the effects of sodium diacetate and fermented juice of epiphytic lactic acid bacteria on the fermentation quality and aerobic stability of total mixed ration(TMR)containing rice straw,winged bean vine,sweet tea residue,and concentrate.Experimental treatments were control(C,no additive),sodium diacetate(S,0.5%FW),the fermented juice of epiphytic lactic acid bacteria(F,2.0 mL/kg FW),sodium diacetate in combination with the fermented juice of epiphytic lactic acid bacteria(0.5%+2.0 mL/kg FW).The TMR materials were ensiled under anaerobic conditions for 35 d at 25℃.All silages were of good quality having low pH values,low ammonia/total nitrogen levels,and low butyric acid content(0.42-0.49 g/kg DM).There were no significant differences(P>0.05)in the lactic acid content and the number of lactic acid bacteria among the control,S,and SL groups.The addition of sodium diacetate did not affect the production of lactic acid by lactic acid bacteria.The introduction of fermented juice of epiphytic lactic acid bacteria inoculation led to improved lactic acid fermentation in the silage.For aerobic stability,S(>312 h)and SL(>302 h)group was higher(P<0.05)than C(>160 h)and L groups(>130 h).Furthermore,with sodium diacetate or in conjunction with the fermented juice of epiphytic lactic acid bacteria,the pH value remained steady at approximately 4.50 following 12 days of aerobic exposure,the acetic acid content was at a high level,and the aerobic stability was prolonged.These findings suggest that the inclusion of 0.5%sodium diacetate can enhance the aerobic stability of TMR silage without compromising fermentation quality.Consequently,it is recommended for implementation in production practices.