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CABI Book Chapter

Modelling nutrient utilization in farm animals.

Book cover for Modelling nutrient utilization in farm animals.

Description

This book presents edited and revised versions of papers presented at the Fifth International Workshop on Modelling Nutrient Utilization in Farm Animals, held at the University of Cape Town, Cape Town, South Africa, 25-28 October 1999. There are 31 chapters and 6 sections entitled ruminal metabolism, absorption and metabolism, growth and development, ruminant production in various situations, nutr...

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Chapter 30 (Page no: 393)

A pig model for feed evaluation.

This chapter describes a dynamic, semi-mechanistic model of growing pigs. The purpose of the model is to predict growth rate and growth composition from given feed inputs and thereby serve as a basis for a new, nutrient-based feed evaluation system for slaughter pigs. The model consists of two submodels, one describing nutrient digestion and absorption, and one describing the metabolism of absorbed nutrients and their retention in the body pools of protein, lipid and ash. Required inputs to the model are: (i) characteristics of the food, such as dry matter content, chemical composition of dry matter, digestibilities and fermentabilities of individual chemical fractions; (ii) characteristics of the pig, such as age at the beginning of simulation, sex, and genetic capacities for protein and lipid retention; and (iii) environmental characteristics such as the ambient temperature. Model outputs are the simulated numeric values of all state and rate variables. From these numbers, the model calculates the predicted pig performance: food intake, retention of protein, lipid, ash and water, production of heat and methane, as well as faecal and urinary excretion of energy and matter. Some examples of simulated data obtained with the model are given in the chapter. The results of simulation were found to be realistic and biologically meaningful. In one test, the model was used to simulate the net energy value of 15 different diets. For each diet, the feed value simulated by the model was closer to the 'true' value determined experimentally than to the value estimated by the present Danish net energy system. It is concluded that a new feed evaluation system for growing pigs is needed. The possibilities and perspectives in the development of such a system based on a dynamic, whole animal simulation model like the one described are discussed.

Other chapters from this book

Chapter: 1 (Page no: 11) The role of thermodynamics in controlling rumen metabolism. Author(s): Kohn, R. A. Boston, R. C.
Chapter: 2 (Page no: 25) Modelling lipid metabolism in the rumen. Author(s): Dijkstra, J. Gerrits, W. J. J. Bannink, A. France, J.
Chapter: 3 (Page no: 37) Towards a more accurate representation of fermentation in mathematical models of the rumen. Author(s): Nagorcka, B. N. Gordon, G. L. R. Dynes, R. A.
Chapter: 4 (Page no: 49) Simple allometric models to predict rumen feed passage rate in domestic ruminants. Author(s): Cannas, A. Soest, P. J. van
Chapter: 5 (Page no: 63) Ruminal metabolism of buffersoluble proteins, peptides and amino acids in vitro. Author(s): Udén, P.
Chapter: 6 (Page no: 73) Models to interpret degradation profiles obtained from in vitro and in situ incubation of ruminant feeds. Author(s): López, S. France, J. Dijkstra, J. Dhanoa, M. S.
Chapter: 7 (Page no: 87) Modelling production and portal appearance of volatile fatty acids in dairy cows. Author(s): Bannink, A. Kogut, J. Dijkstra, J. France, J. Tamminga, S. Vuuren, A. M. van
Chapter: 8 (Page no: 103) Modelling energy expenditure in pigs. Author(s): Milgen, J. van Noblet, J.
Chapter: 9 (Page no: 115) Aspects of modelling kidney dynamics. Author(s): Robson, B. Vlieg, M.
Chapter: 10 (Page no: 127) Evaluation of a representation of the limiting amino acid theory for milk protein synthesis. Author(s): Hanigan, M. D. France, J. Crompton, L. A. Bequette, B. J.
Chapter: 11 (Page no: 145) Multiple-entry urea kinetic model: effects of incomplete data collection. Author(s): Zuur, G. Russell, K. Lobley, G. E.
Chapter: 12 (Page no: 163) Evaluation of a growth model of preruminant calves and modifications to simulate shortterm responses to changes in protein intake. Author(s): Gerrits, W. J. J. Togt, P. L. van der Dijkstra, J. France, J.
Chapter: 13 (Page no: 175) Simulation of the development of adipose tissue in beef cattle. Author(s): Sainz, R. D. Hasting, E.
Chapter: 14 (Page no: 183) A simple nutrient-based production model for the growing pig. Author(s): Boisen, S.
Chapter: 15 (Page no: 197) Second-generation dynamic cattle growth and composition models. Author(s): Oltjen, J. W. Pleasants, A. B. Soboleva, T. K. Oddy, V. H.
Chapter: 16 (Page no: 211) Modelling interactions between cow milk yield and growth of its suckling calf. Author(s): Blanc, F. Agabriel, J. Sabatier, P.
Chapter: 17 (Page no: 227) A mechanistic dynamic model of beef cattle growth. Author(s): Hoch, T. Agabriel, J.
Chapter: 18 (Page no: 241) Modelling nutrient utilization in growing cattle subjected to short or long periods of moderate to severe undernutrition. Author(s): Witten, G. Q. Richardson, F. D.
Chapter: 19 (Page no: 253) An integrated cattle and crop production model to develop whole-farm nutrient management plans. Author(s): Tylutki, T. P. Fox, D. G.
Chapter: 20 (Page no: 263) Modelling nutrient utilization by livestock grazing semiarid rangeland. Author(s): Richardson, F. D. Hahn, B. D. Schoeman, S. J.
Chapter: 21 (Page no: 281) Using the cornell net carbohydrate and protein system model to evaluate the effects of variation in maize silage quality on a dairy farm. Author(s): Tylutki, T. P. Fox, D. G. McMahon, M. McMahon, P.
Chapter: 22 (Page no: 289) Challenge and improvement of a model of post-absorptive metabolism in dairy cattle. Author(s): McNamara, J. P. Phillips, G. J.
Chapter: 23 (Page no: 303) A rodent model of protein turnover to determine protein synthesis, amino acid channelling and recycling rates in tissues. Author(s): Johnson, H. A. Baldwin, R. L. Calvert, C. C.
Chapter: 24 (Page no: 317) Modelling relationships between homoeorhetic and homoeostatic control of metabolism: application to growing pigs. Author(s): Sauvant, D. Lovatto, P. A.
Chapter: 25 (Page no: 329) Model for the interpretation of energy metabolism in farm animals. Author(s): Chudy, A.
Chapter: 26 (Page no: 347) Linear models of nitrogen utilization in dairy cows. Author(s): Kebreab, E. Allison, R. Mansbridge, R. Beever, D. E. France, J.
Chapter: 27 (Page no: 353) Isotope dilution models for partitioning amino acid uptake by the liver, mammary gland and hindlimb tissues of ruminants. Author(s): Crompton, L. A. France, J. Bequette, B. J. Maas, J. A. Hanigan, M. D. Lomax, M. A. Dijkstra, J.
Chapter: 28 (Page no: 361) The conversion of a scientific model describing dairy cow nutrition and production to an industry tool: the CPM dairy project. Author(s): Boston, R. C. Fox, D. G. Sniffen, C. Janczewski, E. Munson, R. Chalupa, W.
Chapter: 29 (Page no: 379) The utilization of prediction models to optimize farm animal production systems: the case of a growing pig model. Author(s): Bailleul, P. J. dit Bernier, J. F. Milgen, J. van Sauvant, D. Pomar, C.

Chapter details

  • Author Affiliation
  • Danish Institute of Agricultural Sciences, Research Centre Foulum, PO Box 50, 8830 Tjele, Denmark.
  • Year of Publication
  • 2000
  • ISBN
  • 9780851994499
  • Record Number
  • 20083014712