菌酶协同对肉牛膨化玉米秸秆型发酵全混合日粮品质的影响

Effect of Bacteria-Enzyme Synergism on Quality of Beef Cattle Puffed Corn Stalk Fermented Total Mixed Ration

为探索玉米秸秆饲用高值化,利用菌酶协同发酵对膨化玉米秸秆进一步深度生物前处理。以55%膨化微贮玉米秸秆为粗饲料,配制水分为45%的肉牛全混合日粮(TMR),分别进行未添加(ck组)、添加布氏乳杆菌(LB组)、复合纤维素酶(ME组)和菌酶(BE组)处理后,密封发酵30 d和有氧暴露7 d,取样分析营养成分、发酵品质、有氧稳定性和黄曲霉毒素B1(AFB1)含量。结果表明:添加菌、酶或菌酶发酵TMR组干物质含量显著低于ck组(P<0.05),ME组和BE组中性洗涤纤维、酸性洗涤纤维、纤维素均显著低于ck组和LB组(P<0.05),BE组半纤维素显著低于ck组(P<0.05);BE组pH最低,且LB、ME、BE组显著低于ck组(P<0.05);ck组与LB组水溶性碳水化合物含量显著低于ME组和BE组(P<0.05),BE组乳酸和乙酸含量显著高于其他组(P<0.05);ck组、LB组、ME组、BE组有氧稳定性分别为62,133,65,143 h,且LB组和BE组平均温度分别在有氧暴露3,4,5,6 d显著低于ck组和ME组(P<0.05);在有氧暴露3,5,7 d时,ck组黄曲霉毒素B1含量显著高于其他各组(P<0.05),且LB组和BE组显著低于ck组和ME组(P<0.05)。利用布氏乳杆菌和复合纤维素酶协同发酵膨化玉米秸秆型TMR,可有效降解TMR结构性碳水化合物,改善发酵品质,提高有氧稳定性,减少AFB1含量。

In order to explore high-value feeding of corn straw,further deep biological pretreatment of puffed corn stalk was carried out by the synergistic fermentation of bacteria and enzymes.In this experiment,55%expanded corn stalk was used as coarse feed,and beef cattle total mixed ration(TMR)with 45%water content was prepared.Beef cattle TMR with no addition(ck group),supplemented with Lactobacillus brucelli(LB Group),compound cellulase(ME group)and bacterialenzyme(BE group)were subjected to sealed fermentation for 30 days and aerobic exposure for 7 days,respectively.Samples were taken to analyze nutrients,fermentation quality,aerobic stability and aflatoxin B1(AFB1)content.The results showed that dry matter content of TMR group was significantly lower than that of ck group(P<0.05),neutral detergent cellulose,acid detergent fiber and crude fiber of ME and BE groups were significantly lower than those of ck and LB groups(P<0.05),and hemicellulose of BE group was significantly lower than that of ck group(P<0.05);pH value of BE group was the lowest,and that of LB,ME and BE groups was significantly higher than that of ck group(P<0.05);Content of water-soluble carbohydrate in ck and LB groups was significantly lower than that in ME and BE groups(P<0.05),and content of lactic acid and acetic acid in BE group was significantly higher than that in other groups(P<0.05);Aerobic stability of ck,LB,ME,BE groups was 62,133,65,and 143 h respectively,and mean temperature of LB and BE groups was significantly lower than that of ck and ME groups at 3,4,5 and 6 d of aerobic exposure respectively(P<0.05);At 3,5 and 7 d of aerobic exposure,content of AFB1 in ck group was the highest,which was significantly higher than that in other groups(P<0.05),and content of AFB1 in LB and BE groups was significantly lower than that in ck and ME groups(P<0.05).Using Lactobacillus brucelli and compound cellulase to ferment puffed corn stalk type TMR can effectively degrade structural carbohydrate of TMR,improve fermentation quality,improve aerobic stability and reduce content of AFB1.