This book brings together the papers presented orally or as posters at the Sixth International Workshopon Modelling Nutrient Utilization in Farm Animals, held in Wageningen, The Netherlands, 6 - 8 September2004. The purpose of this book is to present current research in modelling nutrient digestion andutilization in cattle, sheep, pigs, poultry and fish.The book is organised into six sections that cover a range of topics and modelling approaches; theseare (i) absorption and passage; (ii) growth and development; (iii) mineral metabolism; (iv) methodology;(v) environmental impact; and (vi) animal production and feed evaluation. Deterministic, stochastic,empirical and mechanistic modelling approaches are described.This book will be of significant interest to researchers and students of animal science, particularly thoseconcerned with nutrition modelling.

Table of Contents:
1: Introduction: History and Future Focus, J France, University ofGuelph, Canada 2: The Nordic Dairy Cow Model Karoline - Development of VolatileFatty Acid Sub-Model, J Sveinbjörnsson, P Huhtanen, MTT Afrifood Research Institute,Finland and P Udén, Swedish University of Agricultural Science 3: A Three-Compartment Model of Transmembrane Fluxes of Valineacross the Tissues of the Hindquarters of Growing Lambs Infectedwith Trichostrongylus colubriformis, N C Roy, AgResearch Ltd,Palmerston North, New Zealand, E N Bermingham and W C McNabb 4: Using Rumen Degradation Model to Evaluate Microbial ProteinYield and Intestinal Digestion of Grains in Cattle, P Paengkoum,Suranaree University of Technology, Thailand 5: Simulation of Rumen Particle Dynamics using a Non-Steady StateModel of Rumen Digestion and Nutrient Availability in Dairy CowsFed Sugarcane, E A Collao-Saenz, A Bannink, E Kebreab, University of Guelph, Canada, J France and J Dijkstra 5: Modelling Fluxes of Volatile Fatty Acids from Rumen to PortalBlood, P Nozière, INRA, France and T Hoch 6: The Role of Rumen Fill in Terminating Grazing Bouts of DairyCows under Continuous Stocking, H Z Taweel, WageningenUniversity, Netherlands, B M Tas, S Tamminga and J Dijkstra 7: Functions for Microbial Growth, S López, Universidad de Leon, Spain,M Prieto, J Dijkstra, E Kebreab, M S Dhanoa, Institute of Grassland& Environmental Research (IGER), Wales, UK and J France 8: Obtaining Information on Gastric Emptying Patterns in Horses fromAppearance of an Oral Acetaminophen Dose in Blood Plasma,J P Cant, University of Guelph, Canada, V N Walsh and R J Geor 9: A Model to Evaluate Beef Cow Efficiency, L O Tedeschi, CornellUniversity, USA, D G Fox, M J Baker and K L Long 10: Prediction of Energy Requirement for Growing Sheep with theCornell Net Carbohydrate and Protein System, A Cannas,Universita of Sassari, Italy, L O Tedeschi, A S Atzori and D G Fox 11: Prediction of Body Weight and Composition from Body DimensionMeasurements in Lactating Dairy Cows, T Yan, Agricultural ResearchInstitute, Hillsborough, Ireland, R E Agnew, C S Mayne andD C Patterson 12: Relationships between Body Composition and UltrasonicMeasurements in Lactating Dairy Cows, R E Agnew, T Yan,D C Patterson and C S Mayne 13: Empirical Model of Dairy Cow Body Composition, O Martin,INRA, UMR Physiology de la Nutrition et Alimentation, France andD Sauvant, Institut National Agronomique Paris-Grignon, France 14: Simulating Chemical and Tissue Composition of the GrowingBeef Cattle: From the Model to the Tool, T Hoch, Ph Pradel,P Champciaux and J Agabriel, INRA, France 15: Representation of Fat and Protein Gain at Low Levels of Growth and Improved Prediction of Variable Maintenance Requirement in a Ruminant Growth and Composition Model, J W Oltjen,R D Sainz, A B Pleasants, T K Sobolevaand V H Oddy 16: Growth Patterns of Nellore vs. British Beef Cattle Breeds Assessedusing a Dynamic, Mechanistic Model of Cattle Growth andComposition, R D Sainz, L G Barioni, Embrapa Cerrados, Brazil,P V Paulino, S C Valadares Filho and J W Oltjen 17: A Kinetic Model of Phosphorus Metabolism in Growing Sheep,R Souza Dias ,Center for Nuclear Energy in Agriculture, Brazil,A P Roque, V F Nascimento Filho, D M S S Vitti and I C S Bueno 18: Dynamic Simulation of Phosphorus Utilization in Salmonid Fish,K Hua, University of Guelph, Canada, J P Cant and D P Bureau 19: Development of a Dynamic Model of Ca and P Flows in Layers,J Dijkstra, E Kebreab, R P Kwakkel and J France 20: Estimating the Risk of Hypomagnesaemic Tetany in Dairy Herds,S T Bell, A E McKinnon, Lincoln University, New Zealand and A R Sykes 21: Modelling the Effects of Environmental Stressors on ThePerformance of Growing Pigs: From Individuals to Populations,I J Wellock, Scottish Agricultural College, UK, G C Emmans and I Kyriazakis 22: Empirical Modelling Through Meta Analysis Vs MechanisticModelling, D Sauvant and O Martin 23: Iterative Development, Evaluation and Optimal Parameter Estimationof a Dynamic Simulation Model: A Case Study, L G Barioni,J W Oltjen and R D Sainz 24: Segmented, Constrained, Nonlinear, Multi-objective, DynamicOptimization Methodology Applied to the Dairy Cow RationFormulation Problem, R C Boston, University of Pennsylvania, USAand M D Hanigan, Land O Lakes, Missouri, USA 25: A Model to Simulate the Effects of Different Dietary Strategieson the Sustainability of a Dairy Farm System, A del Prado, Instituteof Grassland and Environmental Research (IGER), UK, D Scholefieldand L Brown 26: Advantages of a Dynamical Approach to Rumen Function to HelpResolve Environmental Issues, A Bannink, J Dijkstra, E Kebreaband J France 27: Evaluation of Models to Predict Methane Emissions from EntericFermentation in North American Dairy Cattle, E Kebreab, J France,B W McBride, N Odongo, A Bannink, J A N Mills and J Dijkstra 28: Investigating Daily Changes in Food Intake by Ruminants,G McL Dryden 29: An Ingredient-Based Input Scheme for Molly, M D Hanigan,H G Bateman, J G Fadel, University of California, USA,J P McNamara and N E Smith 30: Metabolic Control: Improvement of a Dynamic Model ofLactational Metabolism in Early Lactation, J McNamara 31: Rostock Feed Evaluation System - An Example of theTransformation of Energy and Nutrient Utilization Models to Practical Application, A Chudy, FBN / Degussa, Germany 32: The Nordic Dairy Cow Model Karoline - Model Description,A Danfær, P Huhtanen, P Udén, J Sveinbjörnsson and H Volden,Agricultural University of Norway, Norway 33: The Nordic Dairy Cow Model KAROLINE - Model Evaluation,A Danfær, P Huhtanen, P Udén, J Sveinbjörnsson and H Volden 34: A composite model of growth, pregnancy and lactation,K Vetharaniam, AgResearch Limited, New Zealand