灌浆期弱光胁迫对“扬麦15”小麦秸营养价值和体外降解率的影响  

Effects of shading during grain filling on nutritive value and in vitro digestibility of “Yangmai 15” wheat straw

作　　者：李袁飞[1] 何香玉[1] 成艳芬[1] 朱伟云[1] 

机构地区：[1]南京农业大学动物科技学院消化道微生物研究室,江苏南京210095

出　　处：《草业学报》2016年第1期187-196,共10页Acta Prataculturae Sinica

基　　金：公益性行业(农业)科研专项(200903003)资助

摘　　要：本试验采用瘤胃体外降解技术研究了弱光胁迫对小麦秸营养价值及畜禽消化率的影响。试验以弱筋小麦"扬麦15"为材料,在灌浆期进行3个遮阴水平(0%,50%,66%)和3个遮阴时间(2,4,8d)的处理,成熟后统一收取小麦秸,进行营养成分分析并利用体外降解技术评定其体外降解率。营养成分分析结果表明,遮阴水平与遮阴时间均显著影响小麦秸粗蛋白(CP)、中性洗涤纤维(NDF)及中性洗涤可溶物(NDS)含量(P<0.05),但遮阴水平与遮阴时间没有交互作用;遮阴水平由0%增加至66%,小麦秸CP及NDS含量分别由3.06%,23.97%降至2.35%,20.46%,差异显著(P<0.05);而小麦秸NDF含量则由76.03%显著升高至79.54%(P<0.05);遮阴时间由2d增至8d时,小麦秸CP及NDS含量分别由3.11%,23.09%显著降低至2.51%,21.43%(P<0.05),而NDF含量则由76.91%显著升高至78.57%(P<0.05)。体外试验以4头装有永久性瘤胃瘘管的波尔山羊为瘤胃液供体,称量1g小麦秸样品于含有10mL瘤胃液和50mL培养基的39℃发酵瓶内体外发酵,培养72h冰浴终止发酵,测定产气量、pH、体外降解率和发酵液中挥发性脂肪酸。体外降解率结果显示,遮阴水平与遮阴时间均显著影响小麦秸中性洗涤纤维消失率(NDFD),且遮阴水平与遮阴时间没有交互作用,随着遮阴水平增加,小麦秸干物质消失率(DMD)、NDFD及酸性洗涤纤维消失率(ADFD)分别由40.33%,40.82%及36.56%显著降低至35.20%,36.03%及33.36%(P<0.05);随遮阴时间增加NDFD由38.88%显著降低至36.94%(P<0.05)。小麦秸体外降解结果显示,遮阴水平与遮阴时间均显著影响累积产气量(P<0.05),并且存在交互效应;遮阴水平显著影响总挥发性脂肪酸(TVFA)、丁酸产量及乙丙比(P<0.05),遮阴时间对挥发性脂肪酸(VFA)产量及组成没有影响,且遮阴水平与遮阴时间没有交互作用。随遮阴水平增加,小麦秸体外降解累积产气量、TVFA、丁酸产量分别由131.64mL、57.04mmol/L及5.18mmol/L显著降�This study was conducted to investigate the effects of shading during the grain filling stage on the nutritive value and in vitro digestibility of'Yangmai 15'wheat straw.Three shading levels(0%,50%and 66%)and three shade duration periods(2,4and 8days)were compared.At harvest,the wheat straw was collected and stored for analysis of chemical composition and in vitro digestibility and fermentation characteristics.For in vitrofermentation,rumen fluid was collected from 4Boer goats with permanent rumen fistulas.Bottles containing 10 mL rumen fluid and 50 mL media with 1g wheat straw as substrate were incubated at 39℃for 72 h.Gas production was measured throughout the fermentation and samples were collected for analysis of pH,in vitro digestibility and volatile fatty acids(VFA)at the end of fermentation.The results showed that shading level and period significantly affected the crude protein(CP)content,neutral detergent soluble(NDS)and neutral detergent fiber(NDF)(P<0.05)with no interaction between shade level and shade period.When the shade level increased from 0% to 66%,CP and NDS decreased significantly from 3.06% to 2.35%,and23.97%to 20.46%,respectively(P<0.05),while NDF increased significantly from 76.03%to 79.54%(P<0.05).Increasing the shading period from 2to 8days decreased CP and NDS significantly;3.11%to 2.51%,and 23.09%to 21.43%,respectively(P<0.05),while NDF increased significantly from 76.9% to 78.6%(P<0.05).Shade level and shade period significantly affected the neutral detergent fiber digestibility(NDFD)(P<0.05)but no interaction was observed.With increasing shade level dry matter digestibility(DMD),NDFD and acid detergent fiber digestibility(ADFD)decreased significantly from 40.33%,40.82%and 36.56%to35.20%,36.03% and 33.36%,respectively(P<0.05).With increasing shade duration NDFD decreased significantly from 38.88%to 36.94%(P<0.05).Both shade level and shade duration significantly affected gas production(P<0.05)and an interaction between them was observed(P<0.05);gas production decreased significantly

关 键 词：小麦秸 遮阴 营养价值 体外降解 降解率 

分 类 号：S512.1[农业科学—作物学]