The model described by Baldwin and co-workers (Baldwin et al., 1987; Baldwin, 1995) known as Molly utilizes a nutrient-based input scheme, where each nutrient is generally treated as a homogeneous substrate regardless of the source of that nutrient. The exception is a limited, discrete...

A mechanistic, dynamic model of metabolism exists to allow testing of complex hypotheses on nutrient metabolism of the dairy cow. The model describes protein synthesis and degradation in the viscera and muscle, lipogenesis and lipolysis in the adipose tissue, and milk synthesis. It is dynamic,...

This chapter presents a model of metabolism in the sow. A brief description of dynamic, mechanistic, metabolic models is given. The integration of genetic elements into metabolic models is discussed. The modelling process (experimentation, hypothesis setting and improvement) is outlined.

We have been conducting research to improve quantitative descriptions of metabolism in lactating dairy cows depicted in an existing mechanistic, computer-assisted model. The objective was to challenge this model with data collected in in vivo and in vitro experiments on high-producing dairy cattle...

This chapter discusses the quantitative regulatory mechanisms and descriptions of body reserve storage, and its utilization during lactation. It also discusses the body fat reserves and metabolism in dairy cattle, body protein reserves in lactating dairy cattle, and integration of nutrient...

Chemical reactions are controlled either thermodynamically or kinetically. Most mechanistic biological models assume kinetic control of metabolism pathways. The profile of products formed depends on substrate concentrations and enzyme activities, which control the rates of synthesis for competing...

Most mathematical models of the rumen make use of empirical stoichiometric equations to predict the production of fermentation products in the rumen. These models are based on a one, two and three microbial group representation of the total rumen microbial population. The prediction of total VFA...

A database was developed from the literature (36 publications) to explore the mechanisms controlling rumen feed passage rate (K_p) and to predict it. The database included the results of 157 different dietary treatments and passage rate measurements with 45 treatments on dry sheep or wethers, 42 on...

A complex mechanistic model of soluble protein degradation was developed and fitted to literature data of in vitro rumen casein (CAS) and acid-hydrolysed casein (AHCAS) fermentation. Feed amino acid escape was estimated from this model and was compared with estimates made with a simple model of...

Degradation kinetic parameters are usually estimated from degradation profiles obtained using the polyester bag technique or the gas production technique. Models to describe either in situ disappearance curves or gas production profiles were derived from first principles by considering simple...