This book contains 34 chapters on nutrition physiology and presents scientific research in modelling nutrient digestion and utilization in domestic animals, including cattle, sheep, pigs, poultry and fishes. It is divided into 6 parts that cover fermentation, absorption and passage; growth and...

During the 1980s numerous papers had underlined that a mechanistic model would be more appropriate than an empirical one to understand and simulate animal responses to diets. The major criticism against empirical models was the strong limitation of their possibilities of application beyond the...

Parameter estimation and model evaluation are crucial parts of the development of predictive simulation models. However, a lack of synchronization is often observed in the activities of modelling and experimentation in agriculture. One of the causes of the communication gap between modellers and...

In the last meeting of this series of modelling workshops we reported on the development of an optimization scheme for dealing with dairy cow ration formulation, in an optimal way, in the situation where constraints were both non-linear and discontinuous in their arguments. Indeed, we illustrated...

A new model is being developed to study the main elements that affect sustainability within a dairy farm by using multiple goal programming. In this work, we describe the main characteristics of this modelling approach and we evaluate, via optimization, the effect of different dietary strategies...

An extant dynamic model of digestion and absorption of nutrients in cattle fed sugarcane was adapted for non-steady state feeding conditions. This modified model includes mechanisms of particle size reduction and delay in availability of particles and intracellular contents for microbial...

A model was developed that describes the relationships between the production, the ruminal concentrations and the fluxes of volatile fatty acids (VFAs) across portal drained viscera (PDV). This study presents some preliminary results. Firstly, general steady state relationships between production...

Mathematical models of pre- and postnatal growth, pregnancy and lactation were combined and implemented using object-orientated computer code to form an energy-based model of a dairy cow. Each simulated cow 'grows', can have a computer pregnancy with multiple offspring, growing its fetuses to term, ...

Body composition data and live animal measurements were obtained from 146 Holstein × Friesian lactating cows. Live animal measurements were recorded 3 or 4 days prior to slaughter, including live weight (LW), body condition score (BCS), girth, belly girth, height and length. The objective was to...