Hostname: page-component-848d4c4894-pftt2 Total loading time: 0 Render date: 2024-04-30T10:16:47.314Z Has data issue: false hasContentIssue false

A multivariate study of pig carcass growth and composition: 1. production and Grading Characteristics

Published online by Cambridge University Press:  27 March 2009

D. G. Evans
Affiliation:
Meat and Livestock Commission, P.O. Box 44, Queensway House, Bletchley, Milton Keynes, MK2 2EF
A. J. Kempster
Affiliation:
Meat and Livestock Commission, P.O. Box 44, Queensway House, Bletchley, Milton Keynes, MK2 2EF

Summary

Pigs from different companies (source populations) in years 3–5 of the Meat and Livestock Commission's Commercial Pig Evaluation were characterized in terms of eight production characteristics and grading measurements using canonical variates analysis in a multivariate general linear model. For pigs fed to a restricted scale, the first canonical variate was strongly associated with fat thickness measurements and the efficiency with which feed was converted into live-weight gain (FCR); the second canonical variate was associated with killing-out percentage. For pigs fed ad libitum, a discriminant variate formed from the sum of the first two canonical variates was strongly associated with P2 and loin fat thickness measurements and FCR, and a discriminant variate formed from the difference of the first two canonical variates was strongly associated with killing out, length and shoulder fat thickness. The first three canonical variates accounted for 88 and 90% of the variation between source populations for restricted and ad-libitum fed pigs respectively. A graphical display of the source populations indicated that there were six to eight groupings depending on feeding regimen.

In principal component analyses of residual variation, the first principal component on both feeding regimens was strongly associated with fat thickness measurements. The first three principal components accounted for 91 and 90% respectively of the variation for restricted and ad-libitum fed pigs.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1982

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

Cooley, W. W. & Lohnes, P. R. (1971). Multivariate Data Analysis. New York: Wiley.Google Scholar
Evans, D. G. (1982). Canonical and orthogonal discriminant variates in the multivariate general linear model (mimeograph).Google Scholar
Evans, D. G. & Kempster, A. J. (1979). The effects of genotype, sex and feeding regimen on pig carcass development. 1. Primary components, tissues and joints. Journal of Agricultural Science, Cambridge 93, 330347.CrossRefGoogle Scholar
Evans, D. G. & Kempster, A. J. (1982). A multivariate study of pig carcass growth and composition. 2. Dissected tissues and parts. Journal of Agricultural Science, Cambridge 99, 509519.CrossRefGoogle Scholar
Fowler, V. R., Bichard, M. & Pease, A. (1976). Objectives in pig breeding. Animal Production 23, 365388.Google Scholar
Gower, J. C. (1966). A Q-technique for the calculation of canonical variates. Biometrika 53, 588590.Google Scholar
Hazel, L. N. (1943). The genetic basis for constructing selection indices. Genetics 28, 476590.CrossRefGoogle Scholar
Kempster, A. J., Cuthbertson, A. & Harrington, G. (1982). Carcase Evaluation in Livestock Breeding, Production and Marketing. St. Albans: Granada Publishing.Google Scholar
Meat and Livestock Commission (1979). Commercial Pig Evaluation; fifth test report. Meat and Livestock Commission, Bletchley, Bucks.Google Scholar
Meat and Livestock Commission (1980). Commercial Pig Evaluation; management and procedures. Meat and Livestock Commission, Bletchley, Bucks.Google Scholar
Seal, H. (1964). Multivariate Statistical Analysis for Biologists. London: Methuen.Google Scholar