摘要
【目的】本试验旨在探明日粮硝态氮含量对反刍动物瘤胃发酵参数以及微生物合成效率的影响。【方法】配合硝态氮添加水平分别为0、6%、12%、18%、24%和30%的处理日粮,进行双外流连续培养体外发酵,试验期144h。【结果】日粮硝态氮添加水平不影响瘤胃pH值、总挥发酸浓度(P>0.05);随日粮硝态氮添加水平的提高,丙酸摩尔比例上升(Q,P<0.01),乙酸摩尔比例(Q,P<0.01)和NH3-N浓度(L,P<0.01)下降,干物质、有机物和粗蛋白消化率提高(Q,P<0.01)和微生物合成效率(MOEEF)呈二次曲线规律变化(Q,P<0.01)。【结论】硝态氮能被瘤胃微生物所利用。随日粮硝态氮添加水平的提高,瘤胃发酵参数、养分消化率和MOEEF均有不同程度的改变,其中在12%—18%添加水平范围内,MOEFF和瘤胃发酵程度最大,超过此水平有不利影响。
【Objective】 The study was conducted to evaluate the effect of dietary nitrate N addition level on the rumen fermentation and microbial efficiency. 【Method】 The experimental diets were formulated with six dietary nitrate N addition levels including 0,6%,12%,18%,24% and 30%,respectively. The fermentation in vitro was carried out in dual-flow continuous culture system lasting for 144 h. 【Result】 As dietary nitrate N addition level increased,ruminal pH and total VFA of fermenter contents were unchanged （P0.05）,while the molar percentages of propionic acid （Q,P0.01） increased,and acetic acid （Q,P0.01） and ammonia concentration decreased （Q,P0.01）. At the same time,there were quadratic increases （Q,P0.01） in the digestibility of DM,OM and CP. Microbial efficiency （MOEEF） increased quadratically （Q,P0.01） as dietary nitrate N addition level increased. 【Conclusion】 Theses results indicated that dietary nitrate N could be used by ruminal microorganisms. As dietary nitrate N addition level increased,the ruminal fermentation parameters,digestibilities and MOEEF changed in varying degrees. Besides,ruminal MOEEF and fermentability were greater at the dietary nitrate N addition range of 12% to 18%.
出处
《中国农业科学》
CAS
CSCD
北大核心
2010年第16期3418-3424,共7页
Scientia Agricultura Sinica
基金
教育部博士点基金(200800190003)
国家科技支撑计划子课题(2006BAD12B02-06)
