不同刈割条件、青贮添加剂对饲料桑营养价值及其青贮品质的影响  

Effects of Different Cutting Conditions and Silage Additives on Nutritional Value and Silage Quality of Feed Mulberry

作　　者：祝华鑫 黄凌霞[1] 刘红云[1] ZHU Huaxin;HUANG Lingxia;LIU Hongyun(College of Animal Sciences,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学动物科学学院,杭州310058

出　　处：《动物营养学报》2024年第9期6049-6057,共9页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：国家现代农业产业技术体系(CARS-36);中央高校基本科研业务费专项资金资助。

摘　　要：为探究不同刈割条件(株高和留茬高度)及青贮添加剂对饲料桑营养价值及其青贮品质的影响,试验以第4茬刈割期的饲料桑为研究对象,设置不同株高(90、100、110和120 cm)和不同留茬高度(10、20和30 cm),共12个处理,每个处理3个重复,每个重复刈割6株饲料桑,刈割后进行营养评价。然后将株高110 cm、留茬高度30 cm刈割的饲料桑进行青贮试验,设置对照组、糖蜜组(添加22 g/kg糖蜜)和玉米淀粉组(添加15 g/kg玉米淀粉),每组4个重复,于室温青贮70 d后进行营养成分、青贮品质和细菌菌群分析。结果表明:1)在试验设计的株高和留茬高度条件下进行刈割,饲料桑的干物质、粗脂肪、粗灰分、中性洗涤纤维、酸性洗涤纤维含量均无显著差异(P>0.05)。但随着株高的增加,饲料桑纤维素含量有升高趋势,粗蛋白质含量显著下降(P<0.05);留茬高度增加时,饲料桑粗蛋白质含量显著升高(P<0.05)。2)与对照组相比,糖蜜的添加显著提高了青贮粗蛋白质及氨态氮含量(P<0.05),玉米淀粉的添加显著降低了氨态氮含量(P<0.05)。蜜糖或玉米淀粉的添加均显著降低了青贮pH(P<0.05),显著增加了乳酸、乙酸、丙酸含量(P<0.05),提高了青贮发酵品质。3)菌群组成上,糖蜜组厚壁菌门相对丰度低于其他组,各试验组之间乳杆菌属相对丰度一致;基因预测的功能谱显示,糖蜜的添加增强了青贮中核苷酸、聚糖、维生素、能量和其他氨基酸的代谢。综合评价,为了获得较为理想的蛋白质含量且不影响饲料桑的再生,饲料桑的最佳留茬高度为30 cm,株高则可根据实际蛋白质需要进行确定。糖蜜与玉米淀粉均能促进饲料桑的青贮,但糖蜜更具价格优势,因此糖蜜更适合作为饲料桑的青贮添加剂。The experiment was to investigate the effects of different plant heights,stubble heights,and silage additives on the nutritional composition and silage quality of feed mulberry.The feed mulberry in the fourth cutting period was used,and different plant heights(90,100,110 and 120 cm)and stubble heights(10,20 and 30 cm)were set.There were 12 treatments,each treatment had 3 replicates,and each replicate cut 6 feed mulberry.After cutting,the nutritional composition of feed mulberry was measured.Subsequently,research was conducted on feed mulberry with a plant height of 110 cm and a stubble height of 30 cm.Three experimental groups were established for ensiling trials:control group,molasses(MO)group(adding 22 g/kg MO),and corn starch(CS)group(adding 15 g/kg CS).After 70 days of ensiling,the analysis of nutrient components,ensiling quality,and bacterial community were conducted.The results showed as follows:1)there were no significant differences in the contents of dry matter,crude ash,crude fat,neutral detergent fiber,and acidic detergent fiber in feed mulberry under different cutting conditions(P>0.05).As plant height increased,cellulose content tended to increase but crude protein content reduced significantly(P<0.05).Increasing stubble height led to a significant increase in crude protein content(P<0.05),but did not affect protein yield(P>0.05).2)Compared with the control group,the addition of molasses significantly increased the contents of crude protein and ammonia nitrogen(P<0.05),while the addition of corn starch significantly decreased the content of ammonia nitrogen(P<0.05).Incorporating corn starch and molasses in the experimental group led to a significant pH decrease(P<0.05),increased lactic acid,acetic acid,and propionic acid contents(P<0.05),and improved silage quality.3)In terms of bacterial population composition,the relative abundance of Firmicutes reduced in the molasses group,whereas the relative abundance of Lactobacillus was consistent among the experimental groups.The functional spectrum of gene

关 键 词：饲料桑 株高 留茬高度 营养成分 青贮品质 细菌群落 

分 类 号：S816[农业科学—饲料科学]