摘要
The effect of diets varying in level and source of nitrogen (N) and fermentable organic matter on dynamic characteristics of microbial populations in rumen liquor and their impact on substrate fermentation in vitro was studied. The diets tested were straw alone, straw+concentrate mixture and straw+urea molasses mineral block (UMMB) lick. The same diets were taken as substrates and tested on each inoculum collected from the diets. Diet had no effect on the amino acid (AA) composition of either bacteria or protozoa. Differences among the diets in intake, source of N and OM affected bacterial and protozoal characteristics in the rumen. Upper asymptote of gas production (Y) had a higher correlation with bacterial pool size and production rate than with protozoal pool size and production rate. Among the parameters of the gas production model, Y and lag time in total gas has showed significant (p<0.01) correlation with bacterial characteristics. Though the rate constant of gas production significantly differed (p<0.01) between diet and type of straw, it was least influenced by the microbial characteristics. The regression coefficient of diet and type of straw for Y indicated that the effect of diet on Y was threefold higher than that of the straw. As microbial characteristics showed higher correlation with Y, and diet had more influence on the microbial characteristics, gas production on a straw diet could be used effectively to understand the microbial characteristics.
摘要译文
研究了瘤胃液中微生物种群动态特征的氮（N）和可发酵有机物的含量和来源及其对底物发酵的影响。测试的饮食是单独的稻草，稻草+浓缩物混合物和稻草+尿素糖蜜矿物块（UMMB）舔。将相同的饮食作为底物并在从饮食中收集的每个接种物上进行测试。饮食对细菌或原生动物的氨基酸（AA）组成没有影响。摄入的饮食，N和OM的来源之间的差异影响了瘤胃中的细菌和原生动物特征。天然气产量的上渐近线（Y）与细菌池的大小和生产率的相关性高于原生池的大小和生产率。在天然气生产模型的参数中，Y和总气体滞后时间与细菌特征显着（p 0.01）相关。虽然天然气产量的速率常数在饮食和秸秆类型之间显着不同（p 0.01），但它受微生物特征的影响最小。Y的日粮回归系数和稻草类型表明，日粮对Y的影响比稻草高三倍。由于微生物特征与Y的相关性较高，饮食对微生物特征的影响较大，秸秆饲料上的天然气生产可以有效地用于了解微生物特征。
Srinivas, Bandla; Krishnamoorthy, U.;. Influence of Diet Induced Changes in Rumen Microbial Characteristics on Gas Production Kinetics of Straw Substrates In vitro[J]. Asian-Australasian Journal of Animal Sciences, 2005,18(7): 990-996