高精料饲粮中添加烟酸对体外瘤胃发酵培养液pH及发酵参数动态变化的影响  

Effects of Nicotinic Acid Supplementation in High Concentrate Diet on Dynamic Changes of Culture Solution pH and Fermentation Parameters of in Vitro Rumen Fermentation

作　　者：欧阳克蕙[1] 张琪[1] 鲁友友[1] 瞿明仁[1] 熊小文[1] 潘珂[1] 

机构地区：[1]江西农业大学动物科学技术学院,南昌330045

出　　处：《动物营养学报》2014年第1期115-125,共11页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：国家现代农业产业技术体系项目(nycytx-38);国家自然科学基金(31260561);江西省教育厅项目(GJJ13274)

摘　　要：本试验旨在研究高精料饲粮中添加烟酸对体外瘤胃发酵培养液pH及发酵参数动态变化的影响。选用3头体重（275-4-20）kg、安装永久性瘤胃瘘管的锦江黄牛作为瘤胃液供体，培养底物为高精料饲粮（精粗比85：15）。Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别在培养底物中添加0、400、800、1200mg／kg烟酸（干物质基础），每组4个重复。在培养0、0．5、1．0、2．0、4．0、6．0、8．0、12．0、18．0、24．0h取样，测定培养液pH及瘤胃发酵参数。结果表明：1）与Ⅰ组相比，虽然在培养24．0h时各组的培养液pH无显著变化（P〉0．05），但Ⅲ组在6．0～18．0h显著高于Ⅰ组（P〈0．05）；培养24．0h时，与其他各组相比，Ⅲ组显著提高了瘤胃微生物蛋白和氨态氮浓度（P〈0．05），极显著提高了总挥发性脂肪酸浓度（P〈0．01），对乙酸、丙酸、丁酸的浓度没有显著影响（P〉0．05），显著降低了乙酸／丙酸和乳酸浓度（P〈0．05）。2）整体上，烟酸对Ⅱ和Ⅳ组培养液pH和发酵参数的影响均较小，但在培养后期（12．0—24．0h），Ⅳ组有降低微生物蛋白浓度的趋势，且在18．0h时达到显著水平（P〈0．05）。3）在培养0—2．0h，随烟酸添加水平的提高，乳酸净生成速率的波动幅度减小；培养液乳酸浓度与pH呈极显著负相关（R2=-0．957，P〈0．01）。结果提示，高精料饲粮（精粗比85：15）中添加适量烟酸（800mg／kg）可以促进瘤胃微生物的增殖，提高微生物蛋白浓度，促进挥发性脂肪酸产生，同时也提高了氨态氮的浓度，抑制了乳酸生成，减小了乳酸净生成速率的波动幅度，最终减缓了培养液pH的下降速率，避免了pH的剧烈变化。稳定了瘤胃内环境。This study was conducted to investigate the effects of nicotinic acid （NA） supplementation in high concentrate diet on the dynamic changes of culture solution pH and fermentation parameters of in vitro rumen fermentation. Rumen fluid was collected from three Jinjiang cattle [ （275 ± 20 ） kg] fitted with permanent ru- men fistulas. A high concentrate diet （the ratio of concentrate to forage was 85：15） was used. Four levels of NA [ 0, 400, 800 and 1 200 mg/kg （dry matter basis） Ⅰ were supplemented in substrates of groups Ⅰ , Ⅱ, Ⅲ and Ⅳ, respectively, with 4 replicates in each group. The specimen was sampled after being cultured for 0, 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, 12.0, 18.0 and 24.0 h to determine culture solution pH and fermentation parameters. The results showed as follows ： 1 ） compared with group Ⅰ, although no significant difference was found in culture solution pH of different groups after being fermented for 24.0 h （ P 〈 0.05 ）, but that of group Ⅲ was significantly higher after being fermented for 6.0 to 18.0 h （ P 〈 0.05 ） ; compared with the other groups, group Ⅲ significantly increased the concentrations of rumen microbial protein （ P 〈 0.05 ）, ammoni- um nitrogen （P 〈0.05） and total volatile fatty acid （P 〈 0.01 ）, but significantly decreased acetate/propio- nate and lactic acid concentration （ P 〈 0.05 ）, and no significant differences were found in the concentrations of acetate, propionate and butyrate （ P 〉 0.05）. 2 ） Generally, the effects of NA on culture solution pH and fermentation parameters were not obvious in groupsⅡ andⅢ, but microbial protein concentration of group Ⅳ showed a decreasing tendency in late period of fermentation （ 12.0 to 24.0 h）, and the difference reached sig- nificant level at 18.0 h （ P 〈0.05）. 3） at 0 -2.0 h of fermentation, the variation range of net production ef- ficiency of lactate decreased with the increase of NA supplemental level; there was a significant negative c

关 键 词：高精料饲粮 烟酸 pH 瘤胃发酵参数 动态变化 体外法 

分 类 号：S816.7[农业科学—饲料科学] S823[农业科学—畜牧学]