蛋白质来源与粗精料比例对瘤胃体外发酵及微生物的影响

Effects of protein sources and rough concentrate feed ratio on rumen in vitro fermentation and microorganism

本研究旨在确定蛋白质来源和粗饲料与精料比例对瘤胃体外发酵参数的影响。试验采用2×5的因子设计,即2个蛋白来源(木薯蛋白和豆粕),粗料(水稻秸秆)与精料比值分别为80:20、60:40、40:60、20:80和0:100。结果:木薯蛋白组不溶物产气量(b)显著高于豆粕组(P<0.05)。日粮粗料与精料比值对截距值(a)、不溶性馏分产气量(b)、不溶性馏分产气速率常数(c)、潜在产气量(a+b)、累积产气量均有显著影响(P<0.05)。无论蛋白质来源如何,随着日粮粗料与精料比值的升高,干物质和有机物体外消化率显著升高,其中比例为40:60时最高(P<0.05)。与豆粕组相比,酵母发酵木薯蛋白组挥发性脂肪酸总量和丙酸浓度显著提高(P<0.05),而乙酸与丙酸比值及甲烷产量显著降低(P<0.05)。但随着日粮粗料与精料比值的降低,挥发性脂肪酸总量、丙酸及氨氮浓度显著提高(P<0.05),而乙酸、乙酸/丙酸及甲烷产量显著降低(P<0.05),细菌和真菌数量显著增加(P<0.05),原生动物数量显著降低(P<0.05)。结论:酵母发酵木薯蛋白作为蛋白质来源的潜在用途,可提高瘤胃发酵效率和反刍动物的生产能力。

The purpose of this study was to determine the effects of protein source and ratio of roughage to concentrate on in vitro rumen fermentation parameters.The experiment adopted a factor design of 2×5,that is,two protein sources(cassava protein and soybean meal),and the ratio of coarse materials(rice straw)to concentrate was 80:20,60:40,40:60,20:80 and 0:100,respectively.Results:the insoluble gas production(b)of cassava protein group was significantly higher than that of soybean meal group(P<0.05).The ratio of coarse feed to concentrate had significant effects on intercept value(a),gas production rate constant(c),potential gas production rate(a+b)and cumulative gas production rate(P<0.05).No matter what the protein source,the in vitro digestibility of dry matter and organic matter increased significantly with the increase of the ratio of coarse material to concentrate,and the highest ratio was 40:60(P<0.05).Compared with soybean meal group,the total amount of volatile fatty acids and propionic acid concentration in the yeast fermented cassava protein group increased significantly(P<0.05),while the ratio of acetic acid to propionic acid and methane production decreased significantly(P<0.05).However,the total volatile fatty acid,propionic acid and ammonia nitrogen concentration increased significantly with the reduction of the ratio of crude to concentrate(P<0.05),while the production of acetic acid,acetic acid/propionic acid and methane decreased significantly(P<0.05),the number of bacteria and fungi increased significantly(P<0.05),and the number of protozoa decreased significantly(P<0.05).Conclusion:the potential use of yeast to ferment cassava protein as a protein source can improve rumen fermentation efficiency and ruminant production capacity.