碳水化合物与蛋白质同步降解对瘤胃发酵特性及微生物蛋白质合成的影响

本研究通过一系列的体外研究来确定酶和甲醛处理对碳水化合物和蛋白质的降解特性及同步降解碳水化合物和蛋白质对瘤胃体外发酵和微生物蛋白合成的影响。未处理玉米和酶处理玉米与豆粕或酶处理或甲醛处理豆粕相结合,制备6种不同同步指数的试验饲料。结果:使用未经酶处理的玉米时,高同步指数日粮的干物质消化率最高(P<0.05)。但酶处理玉米与各种豆粕混合时,其同步降解对干物质消化率无显著影响(P>0.05)。在所有孵育时间内,含甲醛处理豆粕的日粮氨氮浓度均低于含未处理豆粕日粮和酶处理豆粕日粮(P<0.05),而孵育12和24 h时,酶处理玉米日粮的氨氮浓度低于未处理的玉米日粮(P<0.05)。酶处理玉米组的挥发性脂肪酸总产量和单个挥发性脂肪酸浓度显著高于其他组(P<0.05)。本研究结果提示,可快速发酵的能量和蛋白质来源具有较高的干物质消化率、挥发性脂肪酸产量、氨氮利用率和嘌呤含量。

Effects of simultaneous degradation of carbohydrate and protein on rumen fermentation characteristics and microbial protein synthesis

In this study,a series of in vitro studies were conducted to determine the degradation characteristics of carbohydrates and proteins by enzyme and formaldehyde treatment and the effect of simultaneous degradation of carbohydrates and proteins on rumen fermentation and microbial protein synthesis in vitro.Untreated corn and enzyme-treated corn were combined with soybean meal or enzyme-treated or formaldehyde-treated soybean meal to prepare 6 kinds of experimental feed with different synchronous indexes.Results:the digestibility of dry matter was the highest on the high synchronous index diet(P<0.05).However,when the enzyme treated corn mixed with various soybean meal,its synchronous degradation had no significant effect on dry matter digestibility(P>0.05).During all incubation times,the ammonia nitrogen concentration of the formaldehade-treated soybean meal was lower than that of the untreated soybean meal and enzyme-treated soybean meal(P<0.05),while the ammonia nitrogen concentration of the enzyme-treated corn meal was lower than that of the untreated corn meal at 12 and 24 h of incubation(P<0.05).The total volatile fatty acid production and single volatile fatty acid concentration in enzyme-treated maize group were significantly higher than those in other groups(P<0.05).The results of this study suggest that the energy and protein sources for rapid fermentation have higher dry matter digestibility,volatile fatty acid yield,ammonia nitrogen utilization and purine content.