Matis J H, Wehrly T E, Ellis W C
Department of Statistics, Texas A&M University, College Station 77843.
Biometrics. 1989 Sep;45(3):703-20.
Digesta flow models have been based on linear compartment theory that assumes exponential retention times, and on a generalized theory that incorporates nonexponential (Erlang) retention times (Matis, 1987, Journal of Theoretical Biology 124, 371-376). This paper develops a new family of passage models for heterogeneous digesta by mixing the previous models with assumed parametric, usually gamma, mixing distributions. The utility of the resulting models is demonstrated with experimental data on two treatments, namely a chopped and a ground straw, given to each of four cows. Treatment differences are apparent in the preferred model form and in the means of the estimated mean residence times. The models are relatively easy to fit to data using standard estimation procedures, and they should have broad application to other compartment modeling problems with "heterogeneous particles."
消化物流动模型基于假设指数保留时间的线性隔室理论，以及纳入非指数（埃尔朗）保留时间的广义理论（马蒂斯，1987年，《理论生物学杂志》124卷，371 - 376页）。本文通过将先前的模型与假定的参数混合分布（通常为伽马分布）相结合，开发了一个新的异质消化物通过模型族。用给予四头奶牛的两种处理（即切碎的秸秆和粉碎的秸秆）的实验数据证明了所得模型的实用性。在首选模型形式和估计平均停留时间的均值方面，处理差异很明显。这些模型使用标准估计程序相对容易拟合数据，并且它们应该广泛应用于其他具有“异质颗粒”的隔室建模问题。
