湖羊利用混合挥发性脂肪酸铵的研究——体外试验与前胃消化代谢试验

体外试验研究表明,试验管NH_3-N浓度于培养过程中逐渐下降。而三氯醋酸沉淀蛋白(TCA-P)浓度则迅速上升,2.5小时后超过对照管。同时丁酸向乙酸转化。利用3头装有永久性瘤胃瘘管和皱胃瘘管的湖羊,进行体内试验,以挥发性脂肪酸胺(AS-VFA)替代日粮总氮34％。饲喂后瘤胃NH_3-N、TVFA和丁酸浓度迅速上升,瘤胃内稻草粉纤维素48小时消失率为38.6％,显著高于对照期的31.94％(P<0.05)。试验期1昼夜通过皱胃的总氮量为14.27克,非氨氮(NAN)13.02克,微生物氮4.06克,均有提高趋势。微生物蛋白合成效率提高70％(P<0.01),而前胃有机物消化率则趋于降低。

Studies on Utilizing Ammonium Salts of Volatile Fatty Acid (AS-VFA) in Hu Sheep In vitro and experiments of digestion and metabolism in forestomach

The results of experiments in vitro showed that the NH8.N concentration in the experimental tubes was gradually decreased, Whereas the TCA-P concentration was increased rapidly and 2.5 hours later it exceeded the level of control tubes. There was rapid conversion of butyrate into Acetate. In vivo, the forestomach digestion and metabolism was observed in three Hu sheep fitted with permanent rumen and abomasal cannulas. 34% of total nitrogen in diets was substituted with AS-VFA in the experimental period. The ruminal Ammonium -N, VFA and butyrate concentration increased rapidly after sheep were fed with AS-VFA, and then decreased. The disappearance rate of straw meal cellulose during 48 hours in the rumen (38.62%) was significantly higher than that (i. e. 31.99%)of the control period (p<0.05). The total N, NAN and microbial N passing the abomasum had increasing trend. The rumen digestibility of OM had a decreasing tendency while the efficiency of microbial protein synthesis was increased by 70% (p<0.0l).