草业科学2018，Vol.35Issue(1)：199-207,9.DOI:10.11829/j.issn.1001-0629.2017-0130
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
摘要
Abstract
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士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,inclu-ding a pretest period of 10 days and a test period of 4 days.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 de-tergent fiber (NDF),and acid detergent fiber (ADF)digestibility of the experimental diets,decreasing gradu-ally 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 en-ergy (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 ener-gy 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.Compared with the other two substitutions,30% rice straw or wheat straw had the least variability(P<0.05)in effective energy value.In conclusion,in determination of the effective energy value of rice straw and wheat straw using the substitution method,a significant difference was observed when the substitution proportion was different.In the current study,a rice straw or wheat straw sub-stitution ratio of 30% was better than 10% or 60%.The combination of regression method and substitution method can improve the accuracy of the results when estimating the effective energy value of single roughage for beef cattle,and contribute to acquiring the optimal substitution ratio.关键词
替代法/代谢能/净能/稻草/麦秸/肉牛Key words
substitution method/metabolizable energy/net energy/rice straw/wheat straw/beef cattle分类
农业科技引用本文复制引用
魏明,陈志强,崔志浩,颜培实,王刚,耿广多..替代法估测肉牛对稻草和麦秸的有效能值[J].草业科学,2018,35(1):199-207,9.基金项目
公益性行业(农业)科研专项(201303145) （农业）
国家重点研发计划项目(2016YFD0500508) （2016YFD0500508）
