乳酸菌和纤维素酶对玉米秸秆黄贮饲料品质的影响

Effect of Lactic Acid Bacteria and Cellulase Addition on Fermentation Quality of Corn Stover Silage

旨在研究户外存放时间对玉米秸秆原料品质的影响,探讨存放时间(T)以及添加乳酸菌(LAB)和纤维素酶(CE)对玉米秸秆黄贮饲料发酵品质的影响。设置2个户外存放时间(T1:收获玉米穗后直接黄贮;T2:户外存放5个月后黄贮);每个存放时间设置4个处理,将原料水分含量调节至60%后,分别添加2.0 g/t LAB、2.0 g/t CE、2.0 g/t LAB+2.0 g/t CE(LAB+CE),对照组(CK)不添加任何添加剂,调制黄贮饲料,每个处理重复3次。结果表明,户外存放5个月后,玉米秸秆的可溶性碳水化合物(WSC)、粗蛋白(CP)含量和缓冲能值(BC)显著降低(P<0.05),中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和酸性洗涤木质素(ADL)含量显著增加(P<0.05);玉米穗收获后直接黄贮的p H值和乙酸(AA)含量显著低于存放5个月后调制的黄贮饲料(P<0.05),乳酸(LA)含量、乳酸/乙酸(LA/AA)和氨态氮占总氮量显著高于存放5个月后调制的黄贮饲料(P<0.05);添加LAB后pH值和AA含量显著降低(P<0.05),LA含量和LA/AA显著提高(P<0.05);添加CE后p H值显著降低(P<0.05),LA含量和LA/AA显著提高(P<0.05);T和LAB对发酵品质各项指标有显著影响(P<0.05),CE对pH值、LA和AA含量、LA/AA有显著影响(P<0.05),T和LAB对p H值、AA含量、LA/AA有交互作用(P<0.05)。综上表明,收获玉米穗后应尽快调制玉米秸秆黄贮饲料,添加LAB和CE可有效改善秸秆黄贮饲料的发酵品质,且LAB的添加效果优于CE。

This study aimed to assess the effect of outdoor storage time on quality of corn stover raw material and to evaluate the effect of storage time （T） and lactic acid bacteria （LAB） and cellulase （CE） addition on fermentation quality of corn stover silage. Tow storage time was set in this study （TI： silaging immediately after the harvest of corn cob; T2： silaging after 5-month outdoor storage）; there were four treatments for each storage time and there were three repeats for each treatment; the water content of the raw materials was initially adjusted to 60%, and then the materials were added with 2.0 g/t of LAB, 2.0 g/t of CE, and 2.0 g/t of LAB＋2.0 g/t of CE （LAB＋CE） to prepare silage, respectively; the CK treatment received no additives. The results revealed that compared to the fresh corn stover, the content of water soluble carbohydrate （WSC） and crude protein （CP） as well as buffer capacity （BC） of the corn stover stored for 5 months outdoor was significantly reduced （P〈0.05）, and the content of neutral detergent fiber （NDF）, acid detergent fibre （ADF） and acid detergent lignin （ADL） was significantly increased （P〈 0.05）; compared to the silage prepared with corn stover stored for 5 months, the silage prepared with fresh corn stover had lower pH value and acetic acid （AA） content （P〈0.05） and had higher lactic acid （LA） content, lactic acid/acetic acid （LA/AA） and ammonia nitrogen/total nitrogen （AN/TN,P〈0.05）; the addition of LAB significantly reduced the pH value and AA content （P〈 0.05） and significantly increased the AA content and LA/AA （P〈0.05）; the addition of CE significantly reduced the pH value （P〈0.05） and significantly increased the LA content and LA/AA （P〈0.05）; T and LAB addition had significant effect on all of the indexes associated with fermentation quality （P〈0.05）; CE addition had significant effect on pH value, LA and AA content as well as LA/AA （P〈0.05）; T and LAB addition had significant interactive effect on pH value, AA content and LA/AA （P〈0.05）. The combined data suggest that the silage should be immediately prepared after the harvest of corn cob; the addition of LAB and CE effectively improves the fermentation quality of corn stover silage, and LAB exhibits a better performance than CE.