Hostname: page-component-6d856f89d9-26vmc Total loading time: 0 Render date: 2024-07-16T07:37:24.094Z Has data issue: false hasContentIssue false
  • English
  • Français

A general method for predicting the weight of water in the empty bodies of pigs

Published online by Cambridge University Press:  02 September 2010

G. C. Emmans  and
I. Kyriazakis
G. C. Emmans
Affiliation:
Genetics and Behavioural Sciences Department, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG
I. Kyriazakis
Affiliation:
Genetics and Behavioural Sciences Department, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG
Get access

Abstract

As water is the major component of the pig body its accurate prediction is of importance in pig growth models. It has become conventional to predict the weight of water, WA kg, from the weight of protein, P kg. The purpose of this paper is to find how this can be done across pig genotypes of different mature size. The widely used equation to relate WA to P is of the form: WA = a.Pb. This equation is examined theoretically. It is concluded that the form of the equation is reasonable and, that while the value of the exponent b is likely to be constant across genotypes, the value of the scalar a is not. It is proposed that the value of the scalar a is best estimated as a = WAPRm Pm1·b where WAPRm is the water: protein ratio in the body at maturity and Pm is the weight of protein in the body at maturity. The value of the parameter WAPRm is assumed to be constant across genotypes with a value in the range of 3·04 to 3·20, depending on the methods used for measuring body composition. The general value of b = 0·855, taken from published work, is confirmed. A consequence of the argument quantified in the paper is that the value of a is predicted to vary from a = 4·69 for a pig with Pm = 20 kg to a = 5·36 for a pig with Pm = 50 kg. The general equation is expected to give more accurate predictions of the weight of water and, hence, of body weight, in models intended to predict pig growth, food intake, body composition and efficiency.

Keywords

body proteinbody watergrowthmathematical modelspigs
Type
Research Article
Information
Animal Science , Volume 61 , Issue 1 , August 1995 , pp. 103 - 108
Copyright
Copyright © British Society of Animal Science 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agricultural Research Council. 1981. The nutrient requirements of pigs. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Armsby, H. P. and Moulton, C. R. 1925. The animal as a converter of matter and energy, a study of the role of livestock in food production. Chemical Catalog Company, New York.Google Scholar
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 3:121–145.Google Scholar
Elliot, J. I. and Lodge, G. A. 1977. Body composition and glycogen reserves in the neonatal pig during the first 96 hours post partum. Canadian journal of Animal Science 57:141–150.CrossRefGoogle Scholar
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.153–181.Google Scholar
Emmans, G. C. 1989. The growth of turkeys. In Recent advances in turkey science (ed. Nixey, C. and Grey, T. C.), Poultry Symposium no. 21, pp.135–166. Butterworths, London.Google Scholar
Emmans, G. C. and Fisher, C. 1986. Problems in nutritional theory. In Nutrient requirements of poultry and nutrition research (ed. Fisher, C. and Boorman, K. N.), Poultry symposium no. 19, pp.9–39. Butterworths, London.Google Scholar
Greef, K. H. de. 1992. Prediction of production: nutrition induced tissue partitioning in growing pigs. Ph.D. thesis, Agricultural University ofWageningen, The Netherlands.Google Scholar
Kotarbinska, M. 1969. [An investigation into the transformation of energy in growing pigs.] Institut Zootechniki, Wydewnictwa Wlasne, nr. 238, Wroclaiv.Google Scholar
Kyriazakis, I., Dotas, D. and Emmans, G. C. 1994. The effect of breed on the relationship between feed composition and the efficiency of protein utilisation in pigs. British Journal of Nutrition 71:849–859.CrossRefGoogle ScholarPubMed
Kyriazakis, I. and Emmans, G. C. 1991. Diet selection in pigs: dietary choices made by growing pigs following a period of underfeeding with protein. Animal Production 52:337–346.Google Scholar
Kyriazakis, I. and Emmans, G. C. 1992a. The effects of varying protein and energy intakes on the growth and body composition of pigs. 1. The effects of energy intake at constant, high protein intake. British Journal of Nutrition 68:603–613.CrossRefGoogle ScholarPubMed
Kyriazakis, I. and Emmans, G. C. 1992b. The effects of varying protein and energy intakes on the growth and body composition of pigs. 2. The effects of varying both energy and protein intake. British Journal ofNutrition 68:615–625.CrossRefGoogle ScholarPubMed
Kyriazakis, I., Leus, K., Emmans, G. C., Haley, C. S. and Oldham, J. D. 1993. The effect of breed (Large White × Landrace v. purebred Meishan) on the diets selected by pigs given a choice between two foods that differ in their crude protein contents. Animal Production 56:121–128.Google Scholar
Kyriazakis, I., Stamataris, C., Emmans, G. C. and Whittemore, C. T. 1991. The effects of food protein content on the performance of pigs previously given foods with low or moderate protein contents. Animal Production 52:165–173.Google Scholar
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 30:481–489.CrossRefGoogle Scholar
Moughan, P. J., Smith, W. C. and Stevens, E. v. J. 1990. Allometric growth of chemical body components and several organs in the pig (20-90 kg liveweight). Neiv Zealand Journal ofAgricultural Research 33:77–84.CrossRefGoogle Scholar
Pomar, C., Harris, D. L. and Minvielle, F. 1991. Computer simulation model of swine production systems: 1. Modelling the growth of young pigs, journal of Animal Science 69:1468–1488.CrossRefGoogle Scholar
Stamataris, C., Kyriazakis, I. and Emmans, G. C. 1991. The performance and body composition of young pigs following a period of growth retardation by food restriction. Animal Production 53:373–381.Google Scholar
Taylor, St C. S. 1980a. Genetic size-scaling rules in animal growth. Animal Production 30:161–165.Google Scholar
Taylor, St C. S. 1980b. Genetically standardised growth equations. Animal Production 30:167–175.Google Scholar
Whittemore, C. T. 1983. Development of recommended energy and protein allowances for growing pigs. Agricultural Systems 11:159–186.CrossRefGoogle Scholar
Whittemore, C. T. 1994. Growth and the simulation of animal responses. In Principles of pig science (ed. Cole, D. J. A., Wiseman, J. and Varley, M. A.), pp. 55–73. Nottingham University Press, Nottingham.Google Scholar
Whittemore, C. T. and Fawcett, R. H. 1974. Model responses of the growing pigs to dietary intake of energy and protein. Animal Production 19:221–231.Google Scholar
Whittemore, C. T. and Fawcett, R. H. 1976. Theoretical aspects of a flexible model to simulate protein and lipid growth in pigs. Animal Production 27:87–96.Google Scholar
Whittemore, C. T., Tullis, J. B. and Emmans, G. C. 1988. Protein growth in pigs. Animal Production 46:437–445.CrossRefGoogle Scholar
Whittemore, C. T. and Yang, H. 1989. Physical and chemical composition of the body of breeding sows with differing body subcutaneous fat depth at parturition, differing nutrition during lactation and differing litter size. Animal Production 48:203–212.CrossRefGoogle Scholar