Dhanoa Mewa S, López Secundino, Powell Christopher D, Sanderson Ruth, Ellis Jennifer L, Murray Jo-Anne M D, Garber Anna, Williams Barbara A, France James
Department of Animal BioSci.s, University of Guelph, Guelph, ON N1G 2W1, Canada.
Departamento de Producción Animal, Universidad de León, 24007 León, Spain.
Animals (Basel). 2021 Apr 9;11(4):1069. doi: 10.3390/ani11041069.
Gas production profiles typically show a monotonically increasing monophasic pattern. However, atypical gas production profiles exist whereby at least two consecutive phases of gas production or additional extraneous features that distort the typical profile are present. Such profiles are more likely to occur with the use of a fecal inoculum and are much less well described. The presence of multiple phases or non-descript extraneous features makes it difficult to apply directly recommended modeling approaches such as standard response functions or classical growth functions. To overcome such difficulties, extensions of the Mitscherlich equation and a numerical modeling option also based on the Mitscherlich are explored. The numerical modeling option uses an estimate of relative rate obtained from the smoothed data profile and an estimate of maximum gas produced together with any lag time information drawn from the raw data to construct a simple Mitscherlich equation. In summary, this article illustrates the analysis of atypical gas production profiles obtained using a fecal inoculum and explores the methodology of numerical modeling to reconstruct equivalent typical growth-like trends.
产气曲线通常呈现单调递增的单相模式。然而，存在非典型的产气曲线，即至少有两个连续的产气阶段或存在扭曲典型曲线的其他外在特征。这种曲线在使用粪便接种物时更有可能出现，并且对其描述较少。多个阶段或难以描述的外在特征的存在使得难以直接应用推荐的建模方法，如标准响应函数或经典生长函数。为了克服这些困难，探索了米氏方程的扩展以及同样基于米氏方程的数值建模选项。数值建模选项使用从平滑数据曲线获得的相对速率估计值、最大产气量估计值以及从原始数据得出的任何滞后时间信息来构建一个简单的米氏方程。总之，本文阐述了对使用粪便接种物获得的非典型产气曲线的分析，并探索了数值建模方法以重建等效的典型生长样趋势。
