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Predicting the effects of animal variation on growth and food intake in growing pigs using simulation modelling

  • N. S. Ferguson (a1), R. M. Gous (a1) and G. C. Emmans (a2)


All pig nutrition models to date predict growth responses of either an individual animal or the average animal of a given population over time. Translating the predicted nutrient requirements from the average animal to the population introduces a number of errors as the cause-and-effect response of the average animal is different from the population response. To overcome the problem of estimating the requirements for a given population using models it is necessary to simulate a number of individuals representative of a population and then average these results. This approach however, requires a knowledge of those animal characteristics that vary between individuals and the nature of their distribution. In this paper a scaled growth rate constant (B*), protein weight at maturity (Pm) and the ratio of lipid to protein at maturity (LPRm) are the parameters used to define an individual animal. As no data existed from which the nature of the distribution of B*, Pm and LPRm can be estimated for pigs of different strains and sexes, and due to the impracticality of determining this variability by experimentation, a simulation model was used to estimate the variations within each parameter. In addition this paper quantifies the subsequent effects these distributions have on the genetic variability of average daily gains (ADG) and daily food intake (TI) over a live-weight range of 25 to 90 kg. Comparisons were made between the genetic variation determined by modelling and those published in the literature. The results indicated coefficients of variation for B*, Pm and LPRm of 0·01, 0·05 and 0·10, respectively. An increase in the variability of all three parameters resulted in an increase in the variation in ADG whilst only an increase in the variation of B* and LPRm affected the distribution of FI.



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Black, J. L., Campbell, R. G., Williams, I. H., James, K. J. and Davies, G. T. 1986. Simulation of energy and amino acid utilisation in the pig. Research and Development in Agriculture 3: 121145.
Black, J. L., Flemming, J. F. and Davies, G. T. 1989. Role of computer simulation in the application of knowledge to the animal industries. Proceedings of the 50th Minnesota nutrition conference, pp. 518.
Bridges, T. C., Turner, L. W., Smith, E. A., Stahly, T. S. and Loewer, O. J. 1986. A mathematical procedure for estimating animal growth and body composition. Transactions of the American Society of Agricultural Engineering 29: 13421347.
Cameron, N. D. 1990. Comparison of Duroc and British Landrace pigs and the estimation of genetic and phenotypic parameters for growth and carcass traits. Animal Production 50: 141153.
Cameron, N. D. and Curran, M. K. 1994. Selection for components of efficient lean growth rate in pigs. 4. Genetic and phenotype parameter estimates and correlated responses in performance test traits with ad libitum feeding. Animal Production 59: 281291.
Cameron, N. D., Curran, M. K. and Thompson, R. 1988. Estimation of sire with feeding regime interactions in pigs. Animal Production 46: 8795.
Campbell, R. G. and Dunkin, A. C. 1983. The influence of protein nutrition in early life on growth and development of the pig. 1. Effects on growth performance and body composition. British Journal of Nutrition 50: 605618.
Curnow, R. N. 1973. A smooth population response curve based on an abrupt threshold and plateau model for individuals. Biometrics 29: 110.
Ellis, M., Chadwick, J. P., Smith, W. C. and Laird, R. 1988. Index selection for improved growth and carcass characteristics in a population of Large White pigs. Animal Production 46: 265275.
Emmans, G. C. 1988. Genetic components of potential and actual growth. In Animal breeding opportunities. British Society of Animal Production, occasional publication no. 12, pp. 153181.
Emmans, G. C. and Fisher, C. 1986. Problems in nutritional theory. In Nutrient requirements of poultry and nutritional research (ed. Fisher, C. and Boorman, K. N.), pp. 939. Butterworths, London.
Ferguson, N. S. and Gous, R. M. 1993a. Evaluation of pig genotypes. 1. Theoretical aspects of measuring genetic parameters. Animal Production 56: 233243.
Ferguson, N. S. and Gous, R. M. 1993b. Evaluation of pig genotypes. 2. Testing experimental procedure. Animal Production 56: 245249.
Ferguson, N. S., Gous, R. M. and Emmans, G. C. 1994. Preferred components for the construction of a new simulation model of growth, feed intake and nutrient requirements of growing pigs. South African Journal of Animal Science 24: 1017.
Groebner, D. S. and Shannon, P. W. 1989. Business statistics. Nerrill Publishers, London.
McPhee, C. P., Brennan, P. J. and Duncalfe, F. 1979. Genetic and phenotypic parameters of Australian Large White and Landrace boars performance-tested when offered food ad libitum. Animal Production 28: 7985.
Minitab, . 1994. Minitab reference manual, release 10 for Windows. State College, Pennsylvania.
Moughan, P. J., Smith, W. C. and Pearson, G. 1987. Description and validation of a model simulating growth in the pig (20–90 kg liveweight). New Zealand Journal of Agricultural Research 30: 481490.
Mrode, R. A. and Kennedy, B. W. 1993. Genetic variation in measures of food efficiency in pigs and their genetic relationships with growth rate and backfat. Animal Production 56: 225232.
Phillips, P. A. and MacHardy, F. V. 1982. Modelling protein and lipid gains in growing pigs exposed to low temperature. Canadian Journal ofAnimal Science 62: 109121
Pomar, C., Harris, D. L. and Minvielle, F. 1991. Computer simulation model of swine production systems. I. Modeling the growth of young pigs. Journal of Animal Science 69: 14681488.
Rinaldo, D. and Le Dividich, J. 1991. Assessment of optimal temperature for performance and chemical body composition of growing pigs. Livestock Production Science 29: 6174.
Roux, C. Z. 1976. A model for the description and regulation of growth and production. Agroanimalia 8: 8394.
Standal, N. and Vangen, O. 1985. Genetic variation and covariation in voluntary feed intake in pig selection programmes. Livestock Production Science 12: 367377.
Stewart, T. S. and Schinckel, A. P. 1989. Genetic parameters for swine growth and carcass traits. In Genetics of swine (ed. Young, L. D.), NC-103 research project, Roman Hruska Research Center, Clay Center, Nebraska, USA, pp. 77105.
Taylor, St C. S. 1968. Time taken to mature in relation to mature weight for sexes, strains and species of domesticated mammals and birds. Animal Production 10: 157169.
Whittemore, C. T. 1993. The science and practice of pig production. Longman Scientific and Technical, Essex, UK.
Whittemore, C. T. and Fawcett, R. H. 1976. Theoretical aspects of a flexible model to simulate protein and lipid growth in pigs. Animal Production 22: 8796.
Wyllie, D., Morton, J. R. and Owen, J. B. 1979. Genetic aspects of voluntary food intake in the pig and their association with gain and food conversion efficiency. Animal Production 28: 381390.
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Animal Science
  • ISSN: 1357-7298
  • EISSN: 1748-748X
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