添加烟酸条件下绵羊瘤胃发酵底物降解动力学变化特征

Dynamic Change of Ruminal Fermentation under Niacin Supplement in Sheep

试验用瘤胃液来自3只安装永久性瘤胃瘘管的绵羊,饲喂玉米-豆粕型基础日粮。通过体外试验,添加450mg/kg烟酸,测定在不同培养时间内培养液中NH3-N浓度、瘤胃细菌N产量、原虫数量、总VFA量及乙酸、丙酸、丁酸产量和乙酸/丙酸值的降解动力学特征。结果表明:添加烟酸可提高培养液NH3-N利用率;培养液中细菌N、原虫数、总VFA量及乙酸、丙酸、丁酸产量随采样时间变化而呈不同的动力学变化趋势;但乙酸/丙酸值则不受采样时间变化的影响,与对照组相比差异不显著(P>0.05)。

In this experiment,three sheep fitted with permanent cannule in the rumen and fed a corn-soybean meal based diet were used to investigate the effects of a single dose niacin supplementation on rumen fermentation in vitro. The experiment was divided into two groups（0,450 mg/kg）, there were 10 sampling times, each treatment was incubated 24 h. Parameters for observation included NH3 -N concentration, bacterial N, protozoa number, TVFA, acetate, propionate, butyrate production and acetate to propionate ratio. The rusults indicated that supplemented niacin enhanced NH3-N uptake. Bacterial N ,protozoa numbers,TVFA productionn ,acetate , propionate , butyrate change with the sampling time, but acetate to propionate rate did not change（P〉0. 05）.