替代法估测肉牛对稻草和麦秸的有效能值  

Substitution method for evaluating effective energy value of rice straw and wheat straw for beef cattle

作　　者：魏明[1] 陈志强[1] 崔志浩 颜培实[1] 王刚 耿广多 

机构地区：[1]南京农业大学动物科技学院,江苏南京210095 [2]安徽凤阳大明农牧科技发展有限公司,安徽滁州239000

出　　处：《草业科学》2018年第1期199-207,共9页Pratacultural Science

基　　金：公益性行业(农业)科研专项(201303145);国家重点研发计划项目(2016YFD0500508)

摘　　要：为分析替代法估测肉牛对稻草和麦秸的有效能值及适宜的替代比例,本研究选取12头体重相近(266±13.41)kg的11~12月龄皖东牛公牛,随机分为3组,每组4头牛,分3期进行饲喂试验。第1期:所有供试牛饲喂由带穗玉米青贮组成的基础饲粮,测定基础饲粮的有效能值;第2期和第3期:各组供试牛分别饲喂由稻草或麦秸按不同比例(10%、30%和60%)替代基础饲粮组成的试验饲粮。每期试验14 d,其中前10 d为预饲期,后4 d为正试期。正试期消化代谢和呼吸代谢试验同时进行,测定肉牛对各试验饲粮的能量代谢情况。结果表明,1)与基础饲粮相比,稻草或麦秸替代降低了肉牛对试验饲粮干物质(DM)、粗蛋白(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的表观消化率,且以上指标随替代比例的增加呈逐渐下降趋势。2)基础饲粮组和各替代组之间总能(GE)采食量无明显差异(P>0.05),而消化能(DE)、代谢能(ME)和净能(NE)采食量随稻草或麦秸替代比例的增加而显著降低(P<0.05),总能消化率、总能代谢率和消化能代谢率与稻草或麦秸替代比例呈负相关关系。3)根据不同试验饲粮的有效能值与稻草或麦秸替代比例之间的回归方程,估算得出稻草的DE、ME和NE分别为8.51、5.79和3.64 MJ·kg-1,麦秸的对应值分别为7.89、5.08和3.13 MJ·kg-1;10%、30%和60%3个替代比例中,30%替代比例所计算得稻草或麦秸有效能值的变异度最小(P<0.05)。综上可知,替代比例会影响稻草和麦秸有效能值的测定结果,本研究中稻草或麦秸替代比例为30%时优于10%和60%。在估测单一粗饲料原料有效能值时,回归法和替代法结合能提高测定结果的准确度,也有助于筛选替代法最佳的替代比例。This study aimed to estimate the effective energy value of rice straw and wheat straw for beef cattle using the substitution method,and to investigate the approximate substitution ratio. Twelve Wandong bulls with similar body weight（ 266 ± 13. 41） kg were used and randomly divided into three groups of four bulls each. We conducted three experiments. In Experiment Ⅰ,all animals were fed a whole-crop corn silage based diet and the effective energy value of the basal diet was determined. In Experiment Ⅱ and Experiment Ⅲ,animals were fed experimental diets consisting of the basal diet substituted with different ratios（ 10%,30%,and 60%） of rice straw or wheat straw,respectively（ dry matter（ DM） basis）. Each experiment lasted for 14 days,including a pretest period of 10 days and a test period of 4days. A digestibility trial,integrated with a respirometry trial,was conducted to determine energy metabolism of all experimental diets for beef cattle. Compared with the basal diet group,rice straw or wheat straw substitution decreased the DM,crude protein（ CP）,neutral detergent fiber（ NDF）,and acid detergent fiber（ ADF） digestibility of the experimental diets,decreasing gradually as the rice straw or wheat straw substitution ratio increased. There was no significant difference in gross energy（ GE） intake among all the groups（ P 〉0. 05）,whereas,the digestible energy（ DE）,metabolizable energy（ ME）,and net energy（ NE） intake decreased as the rice straw or wheat straw substitution ratio increased（ P〈 0. 05）. The GE digestibility,GE metabolized,and DE metabolized were also negatively correlated with the substitution ratio of rice straw or wheat straw. According to the regression equation between the effective energy value of different experimental diets and rice straw or wheat straw substitution ratio,the DE,ME,and NE values for rice straw were 8. 51,5. 79,and 3. 64 MJ·kg-1,respectively,and the corresponding values for wheat straw were 7. 89,5. 08,and 3. 13 MJ·kg-1.

关 键 词：替代法 代谢能 净能 稻草 麦秸 肉牛 

分 类 号：S823.924[农业科学—畜牧学]