4种添加剂对饲料桑与脐橙渣混贮品质及微生物多样性的影响

Effects of compound additives on the quality and microbial diversity of mulberry and navel orange residue mixed silage

为探讨复合菌制剂和复合酶制剂对饲料桑(Morus alba)与脐橙(Citrus sinensis)渣混合青贮品质及微生物多样性的影响,设置4个组,分别为对照组(CK,无添加)、复合菌制剂组[J组,添加0.1%植物乳杆菌(Lactobacillus plantarum)和0.05%枯草芽孢杆菌(Bacillus subtilis)]、复合酶制剂组(M组,添加0.01%纤维素酶和0.1%木聚糖酶)、复合菌酶制剂组(JM组,添加0.1%植物乳杆菌、0.05%枯草芽孢杆菌、0.01%纤维素酶和0.1%木聚糖酶),青贮发酵时间为60 d。结果表明:与CK组相比,J组和JM组的干物质含量和粗蛋白含量显著上升(P<0.05);J组、M组和JM组的中性洗涤纤维含量显著(P<0.05)或极显著(P<0.01)下降,M组和JM组的酸性洗涤纤维极显著下降(P<0.01),而J组的酸性洗涤纤维含量无显著变化(P>0.05)。与CK组相比,J组、M组、JM组的pH均极显著降低(P<0.01);J组和JM组的氨态氮/总氮含量极显著下降(P<0.01),而M组无显著差异(P>0.05);J组、M组、JM组的乳酸含量极显著增加(P<0.01),M组的乙酸含量最高,而JM组的丙酸含量最低,且各组均未检测到丁酸。在门水平上,各组优势菌门为厚壁菌门,且相对丰度以JM组最高;其次为变形菌门,相对丰度以CK组最高。在属水平上,CK、M组优势菌属主要以乳杆菌属(Lactobacillus)、肠杆菌属(Enterobacter)和克雷伯氏菌属(Klebsiella)为主,而J、JM组优势菌属主要以乳杆菌属、芽孢杆菌属(Bacillus)和维斯氏菌属(Weissella)为主。综上所述,单独添加复合菌制剂或复合酶制剂均能不同程度地提升饲料桑与脐橙渣混贮的营养价值和发酵品质,还能改善其微生物菌群结构与组成,但联合添加复合菌制剂和复合酶制剂的青贮效果更佳。

The effects of compound bacterial preparations and compound enzyme preparations on the quality and microbial diversity of mulberry and navel orange residue mixed silage were investigated.Four experiment groups were formed:control group(group CK,no addition),compound bacterial preparation group(group J,0.1%Lactobacillus plantarum and 0.05%Bacillus subtilis),compound enzyme preparation group(group M,0.01%cellulase and 0.1%xylanase),and compound bacterial enzyme preparation group(group JM,0.1%Lactobacillus plantarum,0.05%Bacillus subtilis,0.01%cellulase,and 0.1%xylanase).There were three replicates per group,and the silage fermentation time was 60 days.Compared with those of the CK group,the dry matter and crude protein contents of the J and JM groups significantly increased(P<0.05);the neutral detergent fiber content of the J,M,and JM groups significantly decreased(P<0.05).The acid detergent fiber content of the M and JM groups significantly decreased(P<0.01),whereas the acid detergent fiber content of the J group had no significant change(P>0.05).Compared with that of the CK group,the pH of the J,M and JM groups significantly decreased(P<0.01);although the ammonia nitrogen content of the J and JM groups significantly decreased(P<0.01),there was no significant change in group M(P>0.05).The lactic acid content of groups J,M,and JM significantly increased compared with that of the CK group(P<0.01).The acetic acid content of group M was the highest,whereas the propionic acid content of group JM was the lowest.Butyric acid was not detected in any group.The dominant phylum of bacteria in each group was Firmicutes,and its relative abundance was the highest in group JM.This was followed by Proteobacteria,which had the highest relative abundance in the CK group.The dominant bacterial genera in groups CK and M were primarily Lactobacillus,Enterobacter,and Klebsiella,whereas those in groups J and JM were Lactobacillus,Bacillus,and Weissella.In conclusion,adding compound bacterial preparations and compound enzyme preparations separately can improve the nutrient and fermentation quality and the structure and composition of microbial flora;however,the silage effect of the combined addition of compound bacterial enzyme preparations is better.