This book brings together the papers presented orally or as posters at the Sixth International Workshop on Modelling Nutrient Utilization in Farm Animals, held in Wageningen, The Netherlands, 6 - 8 September 2004. The purpose of this book is to present current research in modelling nutrient digestion and utilization in cattle, sheep, pigs, poultry and fish.
The book is organised into six sections that cover a range of topics and modelling approaches; these are (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.
Introduction: History and Future Focus, J France, University of Guelph, Canada; The Nordic Dairy Cow Model Karoline - Development of Volatile Fatty Acid Sub-Model, J Sveinbjornsson, Icelandic Agricultural Research Institute (RALA), Iceland, P Huhtanen, MTT Afrifood Research Institute, Finland and P Uden, Swedish University of Agricultural Science, Sweden; A Three-Compartment Model of Transmembrane Fluxes of Valine across the Tissues of the Hindquarters of Growing Lambs Infected with Trichostrongylus colubriformis N C Roy. AgResearch Ltd, Palmerston North, New Zealand, E N Bermingham and W C McNabb; Using Rumen Degradation Model to Evaluate Microbial Protein Yield and Intestinal Digestion of Grains in Cattle P Paengkoum, Suranaree University of Technology, Thailand; Simulation of Rumen Particle Dynamics using a Non-Steady State Model of Rumen Digestion and Nutrient Availability in Dairy Cows Fed Sugarcane, E A Collao-Saenz, A Bannink, Wageningen University, Netherlands, E Kebreab, University of Guelph, Canada, J France and J Dijkstra, Wageningen University Netherlands; Modelling Fluxes of Volatile Fatty Acids from Rumen to Portal Blood, P Noziere, INRA, France and T Hoch; The Role of Rumen Fill in Terminating Grazing Bouts of Dairy Cows under Continuous Stocking, H Z Toweel, Wageningen University, Netherlands, B M Tas, S Tamminga and J Dijkstra; Functions for Microbial Growth, S Lopez, Universidad de Leon, Spain, M Prieto, J Dijkstra, E Kebreab, M S Dhanoa, Institute of Grassland & Environmental Research (IGER), Wales, UK and J France; Obtaining Information on Gastric Emptying Patterns in Horses from Appearance of an Oral Acetaminophen Dose in Blood Plasma, J P Cant, University of Guelph, Canada, V N Walsh and R J Geor; A Model to Evaluate Beef Cow Efficiency, L O Tedeschi, Cornell University, USA, D G Fox, M J Baker and K L Long; Prediction of Energy Requirement for Growing Sheep with the Cornell Net Carbohydrate and Protein System, A Cannas, Universita of Sassari, Italy, L O Tedeschi, A S Atzori and D G Fox; Prediction of Body Weight and Composition from Body Dimension Measurements in Lactating Dairy Cows, T Yan, Agricultural Research Institute, Hillsborough, Ireland, R E Agnew, C S Mayne and D C Patterson; Relationships between Body Composition and Ultrasonic Measurements in Lactating Dairy Cows, R E Agnew, T Yan, D C Patterson and C S Mayne; Empirical Model of Dairy Cow Body Composition, O Martin, INRA, UMR Physiology de la Nutrition et Alimentation, France and D Sauvant, Institut National Agronomique Paris-Grignon, France; Simulating Chemical and Tissue Composition of the Growing Beef Cattle. From the Model to the Tool, T Hoch, Ph Pradel, P Champclaux and J Agabriel, INRA, France; 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, University of California, USA, A B Pleasants, T K Soboleva and V H Oddy, Meat and Livestock Australia, Australia. Growth Patterns of Nellore vs. British Beef Cattle Breeds Assessed using a Dynamic, Mechanistic Model of Cattle Growth and Composition, R D Sainz, L G Barioni, Embrapa Cerrados, Brazil, P V Paulino, S C Valadares Filho and J W Oltjen; 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; Dynamic Simulation of Phosphorus Utilization in Salmonid Fish, K Hua, University of Guelph, Canada, J P Cant and D P Bureau; Development of a Dynamic Model of Ca and P Flows in Layers, J Dijkstra, E Kebreab, R P Kwakkel and J France; Estimating the Risk of Hypomagnesaemic Tetany in Dairy Herds, S T Bell, A E McKinnon, Lincoln University, New Zealand and A R Sykes; Modelling the Effects of Environmental Stressors on The Performance of Growing Pigs: From Individuals to Populations, I J Wellock, Scottish Agricultural College, UK, G C Emmans and I Kyriazakis; Empirical Modelling Through Meta Analysis Vs Mechanistic Modelling, D Sauvant and O Martin; Iterative Development, Evaluation and Optimal Parameter Estimation of a Dynamic Simulation Model: A Case Study, L G Barioni, J W Oltjen and R D Sainz; Segmented, Constrained, Nonlinear, Multi-objective, Dynamic Optimization Methodology Applied to the Dairy Cow Ration Formulation Problem, R C Boston, University of Pennsylvania, USA and M D Hanigan, Land O Lakes, Missouri, USA; A Model to Simulate the Effects of Different Dietary Strategies on the Sustainability of a Dairy Farm System, A del Prado, Institute of Grassland and Environmental Research (IGER), UK, D Scholefield and L Brown; Advantages of a Dynamical Approach to Rumen Function to Help Resolve Environmental Issues, A Bannink, J Dijkstra, E Kebreab and J France; Evaluation of Models to Predict Methane Emissions from Enteric Fermentation in North American Dairy Cattle, E Kebreab, J France, B W McBride, N Odongo, A Bannink, J A N Mills and J Dijkstra; Investigating Daily Changes in Food Intake by Ruminants, G McL Dryden; 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; Metabolic Control: Improvement of a Dynamic Model of Lactational Metabolism in Early Lactation, J McNamara; Rostock Feed Evaluation System - An Example of the Transformation of Energy and Nutrient Utilization Models to Practical Application, A Chudy, FBN / Degussa, Germany; The Nordic Dairy Cow Model Karoline - Model Description, A Danfaer, P Huhtanen, P Uden, J Sveinbjornsson and H Volden, Agricultural University of Norway, Norway; The Nordic Dairy Cow Model KAROLINE - Model Evaluation, A Danfaer, P Huhtanen, P Uden, J Sveinbjornsson and H Volden; A composite model of growth, pregnancy and lactation, K Vetharaniam, AgResearch Limited, New Zealand.