摘要
试验旨在研究饲粮中粗蛋白质和淀粉水平对瘤胃发酵特性的影响,探索在较低粗蛋白质水平下最佳的淀粉含量。采用2×3双因素试验设计,通过调控配方中豆粕、玉米与全株玉米青贮的比例改变发酵底物中粗蛋白质和淀粉水平,在两种粗蛋白(CP)水平(10.50%和13.00%)下,分别设计低、中、高3种淀粉水平(20.00%、30.00%和40.00%),共设6组,每组3个重复,测定24、48 h产气量(GP)、干物质降解率(DMD)、pH值、氨态氮(NH-N)浓度、微生物蛋白(MCP)浓度及挥发性脂肪酸(VFA)的浓度。结果显示:粗蛋白质和淀粉水平对24、48 h的GP、DMD、pH值、NH_(3)-N浓度、MCP浓度均具有显著影响(P<0.05);淀粉水平显著影响VFA含量(P<0.05)。CP含量为10.50%时,中、高淀粉水平组DMD、GP、发酵参数差异不显著(P>0.05);CP水平为13.00%时,pH值、NH-N浓度、乙酸含量、乙酸/丙酸值随淀粉含量的升高而显著降低(P<0.05);淀粉水平一定时,随着粗蛋白质水平升高,pH值和NH_(3)-N浓度显著降低(P<0.05),GP、DMD、MCP浓度显著提高(P<0.05)。研究表明,适当提高饲粮中蛋白和淀粉水平可一定程度地改善瘤胃发酵参数;较低粗蛋白质饲粮条件下,淀粉水平在30.00%~40.00%时瘤胃发酵效果较好。
The experiment was to study the effect of dietary crude protein and starch levels on rumen fermentation characteristics,to explore the best starch content under different crude protein levels.2×3 two-factor experimental design was used to change the crude protein level and starch level of fermentation substrate by adjusting the ratio of soybean meal and corn to whole-plant corn silage.Low,medium and high starch levels(20%,30%and 40%)were designed at two crude protein levels(10.50%and 13.00%).There were six treatments,with three replicates in each treatment.24 and 48 h GP,DMD,pH value,NH_(3)-N,MCP and VFA concentration were measured.The results showed that crude protein level and starch level had significant effect on 24 h and 48 h GP,DMD,pH value,NH_(3)-N concentration and MCP concentration(P<0.05),and starch level significantly affected the content of volatile fatty acids(P<0.05).The effect of starch level on GP,MCP concentration and propionic acid content were different under different CP levels.When CP level was 10.50%,there was no significant difference in dry matter degradation rate,gas production and fermentation parameters between middle and high starch level groups,but when CP level was 13.00%,pH value,NH_(3)-N concentration,acetic acid content and acetic acid/propionic acid ratio decreased significantly with the increase of starch level.When the starch level was constant,the concentrations of pH value and NH_(3)-N decreased significantly,while the gas production,dry matter degradation rate and MCP concentration increased significantly with the increase of crude protein level.The study indicates that properly increasing the protein level and starch level in diet can improve the fermentation parameters to a certain extent.Under the condition of lower crude protein diet,the rumen fermentation effect was better when the starch level was 30%~40%.
作者
刘青玉
李秋凤
曹玉凤
李树静
张秀江
肖阳
梁英杰
赵超
LIU Qing-yu;LI Qiu-feng;CAO Yu-feng;LI Shu-jing;ZHANG Xiu-jiang;XIAO Yang;LIANG Ying-jie;ZHAO Chao
出处
《饲料研究》
CAS
北大核心
2022年第13期1-5,共5页
Feed Research
基金
河北省优质粗饲料防霉及高效利用关键技术(项目编号:19226615D)
河北省二期现代农业产业技术体系肉牛创新团队高效养殖岗位建设项目(项目编号:HBCT2018130202)
国家现代农业产业技术体系(项目编号:CARS-37)。
关键词
体外产气法
粗蛋白质
淀粉
干物质降解率
in vitro gas test
crude protein
starch
dry matter degradation rate
