不同蛋白质来源的日粮对瘤胃发酵特性及蛋白质消化的影响

Effects of diets differing in protein sources on rumen fermentation and protein digestion

以4只安装永久性瘤胃瘘管的白山羊作为采集瘤胃液的供体,用体外法研究了4种不同蛋白质来源(玉米-豆粕型、玉米-豆粕-棉粕型、玉米-豆粕-菜粕型、玉米-棉粕-菜粕型)的日粮对不同培养时间的发酵底物的干物质和蛋白质消化率、产气量、瘤胃pH值和NH3-N质量浓度的影响。结果表明:经24 h人工瘤胃培养后,干物质和蛋白质的消化率由高到低顺序依次为:玉米-豆粕型>玉米-豆粕-棉粕型>玉米-豆粕-菜粕型>玉米-棉粕-菜粕型。发酵底物产气量由高到低依次为:玉米-豆粕-菜粕型>玉米-豆粕-棉粕型>玉米-豆粕型>玉米-棉粕-菜粕型。瘤胃NH3-N质量浓度由高到低依次为:玉米-豆粕-棉粕型>玉米-豆粕-菜粕型>玉米-豆粕型>玉米-棉粕-菜粕型。各组的瘤胃pH值基本一致,处于正常瘤胃生理范围。

Four diets with different protein resources （corn-soybean meal, CS; corn-soybean-cotton seed meal, CSCS; corn-soybean-rapeseeds meal, CSRS; corn-cotton seed-rapeseed meal, CCSRS） were fermented in vitro for 24 hours with the rumen fluid collected from four cannulated goats to evaluate the effect of dietary protein sources on disappearance of dry matter and protein, gas production, pH value and NH3 --N concentration. The results showed that the order of digestion rate of four diets incubated 24 hours by artificial rumen was CS〉CSCS〉CSRS〉CCSRS; the order of the gas production was CSRS〉CSCS〉CS〉CCSRS; the order of NH3-N concentration was CSCS〉CSRS〉CS〉 CCSRS. No difference among diets was found in pH value and all pH values were in the normal physiological range.