Resumen

VARGAS-VILLAMIL, Luis; KU-VERA, Juan; VARGAS-VILLAMIL, Felipe  y  MEDINA-PERALTA, Salvador. Modelo para la estimación de tres parámetros ruminales biológicos. INCI [online]. 2004, vol.29, n.6, pp.296-302. ISSN 0378-1844.

A mechanistic deterministic dynamic model (Turix v1.0) was described that is useful as the base of a regression function during the fitting of three parameters associated with a closed system of ruminal bacterial growth. The model parameters estimated are: k_M,SmL describes the performance of the substrate uptake process, k_LM describes the performance of the bacterial growth from an intermediate metabolite, and Y_PAGV,FS describes the performance of the fermentation products microbial yield. The model of 11 state variables is based on the concepts of Monod, Michaelis-Menten and black box models, as well as on available information. This model does not use the steady state assumption on biomass and fermentation products variable states and assumes that the concentration of the microbial substrate is directly proportional to itself and to the microbial biomass concentration, as well as to the presence of an intermediate metabolite. Besides, it is assumed that the biomass and volatile fatty acids concentration, within the system, are a function of an intermediate metabolite. To describe the system performance three sub-models were developed: Feed degradation, bacterial growth and bacterial fermentation. The parameters were estimated solving a regression problem which involves a set of differential equations. The basic concepts utilized during the development of the Turix model are discussed. The model was able to adjust the k_{M, SmL}, k_LM and Y_{PAGV, SF} parameters related with kinetic process and fermentation products which are useful to understand a close system of ruminal bacterial growth.

Palabras clave : Crecimiento Microbiano; Modelos; Parámetros; Rumiantes.