摘要
利用非同位素标记丙酸的启动—连续灌注的方法 ,采用非标记酸灌注条件下计算丙酸基本产生量的原理 ,研究了绵羊瘤胃碳水化合物产生丙酸的基本速率和通过灌注提高丙酸产生速率后 ,丙酸在瘤胃的消失率 ,离开瘤胃的流通速率 ;丙酸在瓣胃和真胃及小肠的吸收及其它有关液相指标的影响。研究表明 :当试验绵羊饲喂粗精比为 5 4∶46的日粮并满足维持饲养水平时 ,测得的丙酸基本产生速率为 2 2 4mmol/h ,瘤胃丙酸库容量为 5 1 94mmol,仅占丙酸日产量的 9 6 % ;还确定了瘤胃灌注丙酸后获得稳态的条件是 :瘤胃液相 pH的变异系数CV <0 5 % ,丙酸浓度的变异系数 <6 % ,标记物Co浓度的变异系数 <5 % ;丙酸在瘤胃的吸收速率与其在瘤胃的产生速率成正比 (P <0 0 1) ,当丙酸的产生速率从 37 14提高至 145 0 7mmol/h时 ,瘤胃吸收的丙酸占丙酸产生量的 2 /3以上 ,而随液体离开瘤胃的丙酸不足丙酸产生量的 1/3。进一步的研究证实 ,离开瘤胃的丙酸在瓣胃和真胃有96 %以上被吸收 ,有 3%～ 4%进入十二指肠 ;同时还获得了一系列通过瘤胃丙酸产生速率 (PROD丙酸 ,mmol/h)
A pulse continuous buffer solution with non labeled propionate was introduced to the rumen of the sheep to reach rumen steady state,and basal rumen propionate production rate (mmol/h) from the fermentation of dietary carbohydrate in the rumen,disappearance and passage of propionate in the rumen,disappearance of propionate in the omasum,abomasum and small intestine,and some rumen liquid phase indexes were investigated after propionate production rate was elevated by infusing different levels of non labeled propionate solution.The results indicated that basal propionic acid production rate was 22 4 mmol/h,and the pool size of propionate was 51 94 mmol which was 9 6% of propionic production per day in the sheep fed a 54% ground hay 46% corn based concentrate diet eight times a day at maintenance energy level,and some parameters for rumen steady state condition were found as follows:CV of fluid pH was <0 5%,CV of propionic concentration was <6% and CV of Co concentration of label was less then 5%.Ruminal disappearance of propionate was linearly related to its rate of production (P<0 01),but the fraction of total production from 68% to 71% disappeared from the rumen when the production rate of propionic acid was elevated from 37 14 mmol/h to 145 07 mmol/h.Conversely,approximately 29%～32% passed out the rumen to the remainder parts of the stomach and intestines.It was suggested that more than 96% propionate flowed out the rumen was absorbed in the omasum and abomasum,and the remainder 4% entered into the small intestine.At the same time a series of relationship equations were established based on the data of the production rate of propionate (PROD prop ,mmol/h) in the rumen and other indexes obtained.
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
2002年第1期6-13,共8页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
