Schulin-Zeuthen M, Lopes J B, Kebreab E, Vitti D M S S, Abdalla A L, Haddad M Del, Crompton L A, France J
Centre for Nutrition Modelling, Department of Animal and Poultry Science, University of Guelph, Guelph, Ont., Canada.
J Theor Biol. 2005 Sep 21;236(2):115-25. doi: 10.1016/j.jtbi.2005.02.021. Epub 2005 Apr 18.
A comparison of the models of Vitti et al. (2000, J. Anim. Sci. 78, 2706-2712) and Fernández (1995c, Livest. Prod. Sci. 41, 255-261) was carried out using two data sets on growing pigs as input. The two models compared were based on similar basic principles, although their aims and calculations differed. The Vitti model employs the rate:state formalism and describes phosphorus (P) flow between four pools representing P content in gut, blood, bone and soft tissue in growing goats. The Fernández model describes flow and fractional recirculation between P pools in gut, blood and bone in growing pigs. The results from both models showed similar trends for P absorption from gut to blood and net retention in bone with increasing P intake, with the exception of the 65 kg results from Date Set 2 calculated using the Fernández model. Endogenous loss from blood back to gut increased faster with increasing P intake in the Fernández than in the Vitti model for Data Set 1. However, for Data Set 2, endogenous loss increased with increasing P intake using the Vitti model, but decreased when calculated using the Fernández model. Incorporation of P into bone was not influenced by intake in the Fernández model, while in the Vitti model there was an increasing trend. The Fernández model produced a pattern of decreasing resorption in bone with increasing P intake, with one of the data sets, which was not observed when using the Vitti model. The pigs maintained their P homeostasis in blood by regulation of P excretion in urine.
以两个生长猪数据集作为输入，对维蒂等人（2000年，《动物科学杂志》78卷，2706 - 2712页）和费尔南德斯（1995年c，《畜牧生产科学》41卷，255 - 261页）的模型进行了比较。所比较的两个模型基于相似的基本原理，尽管它们的目标和计算方法有所不同。维蒂模型采用速率 - 状态形式主义，描述了生长山羊肠道、血液、骨骼和软组织中磷（P）含量的四个库之间的磷流动。费尔南德斯模型描述了生长猪肠道、血液和骨骼中磷库之间的流动和部分再循环。两个模型的结果均显示，随着磷摄入量的增加，从肠道到血液的磷吸收以及骨骼中的净保留呈现相似趋势，但使用费尔南德斯模型计算的数据集2中65千克体重的结果除外。对于数据集1，费尔南德斯模型中血液回肠内源性损失随磷摄入量增加的速度比维蒂模型更快。然而，对于数据集2，使用维蒂模型时内源性损失随磷摄入量增加而增加，但使用费尔南德斯模型计算时则下降。在费尔南德斯模型中，磷掺入骨骼不受摄入量影响，而在维蒂模型中有增加趋势。费尔南德斯模型显示随着磷摄入量增加骨骼再吸收减少的模式，而使用维蒂模型时在其中一个数据集中未观察到这种情况。猪通过调节尿液中的磷排泄来维持血液中的磷稳态。
