日粮硝酸盐水平对湖羊瘤胃硝态氮动态消失率、发酵参数及血液高铁血红蛋白含量的影响  

Effects of dietary nitrate dosage on ruminal nitrate disappearance rate,fermentation parameters and concentration of blood methemoglobin of Hu Sheep

作　　者：陈志远[1] 马婷婷[1] 方伟[1] 左晓昕 林淼[1] 赵国琦[1] 

机构地区：[1]扬州大学动物科学与技术学院,江苏扬州225009

出　　处：《草业学报》2016年第2期95-104,共10页Acta Prataculturae Sinica

基　　金：江苏省博士后科研资助计划(1402114C);江苏高校优势学科建设工程资助项目资助

摘　　要：本试验研究日粮硝酸盐的添加量对湖羊瘤胃还原硝态氮程度和对发酵参数及血液高铁血红蛋白的影响.试验选取6头湖羊,采用随机区组试验设计,每期分别饲喂含0%,1%,2%,3%,4%,5%硝酸钾的日粮.测定喂后0,0.5,1.0,1.5,2.0,4.0,6.0,8.0h瘤胃液硝酸盐和亚硝酸盐含量及瘤胃发酵参数.晨饲后2.0h通过颈静脉采血,测定高铁血红蛋白含量.结果表明,湖羊在采食1.0h后硝酸盐含量达到最高（0.95～2.14g/L）,之后快速消失,亚硝酸盐含量在喂后1.5h达到最高（0.93～6.22μmol/L）,之后降低.高铁血红蛋白的含量随硝酸盐添加量的增加而显著升高（P〈0.01）,最高达0.32%.添加硝酸盐显著提高瘤胃液pH 值（P〈0.01）和2.0h的氨态氮含量（犘〈0.01）以及乙酸/丙酸,添加量高于3%会降低微生物蛋白和总挥发性脂肪酸的浓度,2%的硝酸盐添加量微生物蛋白和总挥发性脂肪酸的合成量最高,最有利于微生物发酵.This study investigated the effects of dietary nitrate dosage on ruminal nitrate disappearance rate, fermentation parameters and blood methemoglobin of Hu sheep.The experiment used a randomized block de-sign.Six selected Hu sheep were fed different levels of dietary potassium nitrate (0%,1%,2%,3%,4%, 5% of DM intake).The concentration of nitrate,nitrite and fermentation parameters in rumen fluid were ob-tained 0,0.5,1.0,1.5,2.0,4.0,6.0 and 8.0 h after feeding.In addition,the concentration of blood methe-moglobin was determined 2.0 h after feeding through blood collection from the jugular vein.The nitrate con-centration increased to a maximum value (0.95-2.14 g/L)at 1.0 h after feeding,then reduced rapidly.The nitrite concentration increased to maximum value (0.93 -6.22 μmol/L)1.5 h after feeding.The content of methemoglobin significantly increased with the nitrate addition (P <0.01),to a peak of 0.32% at 5% dietary potassium nitrate.Nitrate addition also significantly increased rumen fluid pH value,ammonia nitrogen con-centration and acetic acid/propionic acid 2.0 h after feeding (P <0.01).In conclusion,potassium nitrate addi-tion at over 3% of DM intake was found to reduce the concentration of microbial protein and total volatile fatty acids.Microbial protein synthesis and total volatile fatty acids were highest with 2% potassium nitrate addi-tion,and the dosage of 2% potassium nitrate was beneficial to rumen fermentation.

关 键 词：微生物蛋白 硝酸盐还原 瘤胃发酵 添加量 

分 类 号：S826.5[农业科学—畜牧学]