添加麦麸对饲料油菜与玉米秸秆混贮品质的影响  

Effects of wheat bran supplementation on the quality of mixed silage from feed rape and corn straw

作　　者：杨洁 杨仪[1,2,3] 丁园 刘辉[1,2] 王京 辛国省 YANG Jie;YANG Yi;DING Yuan;LIU Hui;WANG Jing;XIN Guosheng(School of Life Science,Ningxia University,Yinchuan 750021,Ningxia,China;Ningxia Feed Engineering Technology Research Center,Yinchuan 750021,Ningxia,China;Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China,Yinchuan 750021,Ningxia,China;Ningxia Haobiao Analysis and Testing Research Institute,Yinchuan 750021,Ningxia,China)

机构地区：[1]宁夏大学生命科学学院,宁夏银川750021 [2]宁夏饲料工程技术研究中心,宁夏银川750021 [3]西部特色生物资源保护与利用教育部重点实验室,宁夏银川750021 [4]宁夏昊标检测服务研究院,宁夏银川750021

出　　处：《草业科学》2020年第12期2594-2602,共9页Pratacultural Science

基　　金：宁夏回族自治区重点研发计划项目(2018BBF02003、2019BBF02016)。

摘　　要：碳源是影响青贮饲料发酵品质的重要因素。本研究以调制好的水分含量为60%的麦麸作为碳源,探究其添加水平对饲料油菜(Brassica napus)与玉米(Zea mays)秸秆混贮品质的影响,将饲料油菜与玉米秸秆按照2∶1均匀混合,麦麸添加水平设置为0、2%、4%、6%、8%、10%。分别在第3、7、15、23、30、45、60天取样测定pH,并在第60天进行感官评定、主要营养物质含量和发酵指标的测定。结果表明:发酵60 d后,麦麸添加组饲料油菜与玉米秸秆混贮品质显著提升,其感官评分均高于13分;整个发酵过程以7 d前下降速度最快,组间差异明显,试验结束时各组pH均可降至4.25以下。营养物质分析发现,10%麦麸添加组的粗蛋白(crude protein,CP)、粗脂肪(ether extract,EE)、粗灰分(Ash)含量显著高于其他组(P<0.05),中性洗涤纤维(neutral detergent fiber,NDF)和酸性洗涤纤维(neutral detergent fiber,ADF)含量均显著低于其他组(P<0.05)。发酵参数组间分析发现,10%麦麸添加组的氨态氮含量、氨态氮占总氮比例显著低于其他组(P<0.05),对照组氨态氮占总氮比例最高,达6.09%;乳酸含量也存在显著的组间差异性(P<0.05),以10%添加组乳酸含量最高,达89.83 g·kg^−1。挥发性脂肪酸组成分析发现,乙酸含量最高,丁酸均未检测出;乙酸、丙酸均存在显著的组间差异性(P<0.05),对照组乙酸含量最高,达19.02 g·kg^−1,10%添加组的丙酸含量最高,达0.87 g·kg^−1。综上所述,麦麸的添加水平显著影响饲料油菜与玉米秸秆混合青贮的品质,其中麦麸添加量为10%时,可获得品质较高的混贮饲料。The carbon source is an important factor that affects the fermentation quality of silage.The present study was conducted to investigate the effects of wheat bran addition as a carbon source on the quality of mixed feed rape and corn straw silage.Fresh feed rape and corn straw were evenly mixed at a proportion of 2∶1.Wheat bran,with a humidity 60%,was then added as the carbon source at 0,2%,4%,6%,8%,and 10%.The pH value of the mixed silage was measured on the 3rd,7th,15th,23rd,30th,45th,and 60th days.The evaluations of the sensory characteristics,main nutrient contents,and fermentation index were performed on the 60th day.The results demonstrated that the fermentation quality of feed rape and corn straw silage with wheat bran improved remarkably after 60 days,and the sensory scores were all higher than 13 points.The pH values of each group decreased significantly(P<0.05),with the fastest reduction before 7 days.The pH value of each group decreased to below 4.25 by the end of the experiment.Nutrient analysis found that the CP,EE,and ash contents in the group with 10%wheat bran addition was significantly higher than those in the other groups(P<0.05).Meanwhile,the NDF and ADF contents in the group with 10%wheat bran were significantly lower than those in the other groups(P<0.05).The analysis of the fermentation parameters showed that the ammonia nitrogen content and proportion of ammonia nitrogen in the total nitrogen in the 10%wheat bran group were significantly lower than those in the other groups(P<0.05).The ammonia nitrogen in the total nitrogen reached the highest ratio of 6.09%in the 0 wheat bran group.Meanwhile,there were also significant intergroup differences concerning the lactic acid content(P<0.05),with the maximum lactic acid content of 89.83 g·kg^−1 being reached in the 10%group.The analysis of the volatile fatty acid composition demonstrated that acetic acid was the most abundant in each group,while no butyric acid was detected.There were significant intergroup differences for both acetic and prop

关 键 词：碳源 混贮 感官评定 营养品质 发酵品质 氨态氮 挥发性脂肪酸 

分 类 号：S816.53[农业科学—饲料科学]