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Differences in the composition and tissue distribution of pig carcasses due to selection and feeding level

Published online by Cambridge University Press:  02 September 2010

N. W. Godfrey
Affiliation:
Department of Agriculture, Baron-Hay Court, South Perth, Western Australia 6151, Australia
P. G. Frapple
Affiliation:
Department of Agriculture, Baron-Hay Court, South Perth, Western Australia 6151, Australia
A. M. Paterson
Affiliation:
Department of Agriculture, Baron-Hay Court, South Perth, Western Australia 6151, Australia
H. G. Payne
Affiliation:
Department of Agriculture, Baron-Hay Court, South Perth, Western Australia 6151, Australia
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Abstract

A total of 96 Large White weaner pigs, comprising equal numbers of entire males and females, and of controls and eighth generation index-selected genotypes, were fed ad libitum until 40 kg live weight. From 40 kg until slaughter at 85 kg live weight pigs within genotype and sex groups were fed either ad libitum or 2·2 times maintenance. The left sides of the carcasses were divided into shoulder, middle and ham portions and the middles further divided into eye, wedge and belly dorso-ventral portions. Tissue dissection was performed on all portions separately.

Selected pigs yielded proportionately 0·15 less fat, 0·08 more muscle, a smaller muscle: bone ratio and 4·05 mm less P2 backfat depth than the controls. When the data were adjusted to the same mean P2 fat depth, the carcasses of selected pigs had 0·07 less fat and 0·03 more muscle. There were no appreciable differences between the genotypes in cranio-caudal tissue distribution. However, there were differences in dorso-ventral tissue distribution since the middles of selected pigs had proportionately and absolutely more of each tissue in the belly. There was no evidence that selection against fat at the P2 site had caused any increase in fat lateral to the m. longissimus.

Food restriction increased carcass muscle by 0·10 and decreased fat by 0·17, but had no effect on muscle: bone ratio or cranio-caudal or dorso-ventral tissue distribution. At the same carcass side weight and P2 fat depth, restricted feeding decreased fat by 0·10 and increased muscle by 0·06 in the carcass side.

It is concluded that carcasses of the selected pigs would be undervalued relative to the controls due to less fat and more muscle at the same weight and P2 fat depth. Also, restriction on food intake can cause carcasses to be undervalued relative to feeding ad libitum.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1991

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References

Agricultural Research Council. 1981. The nutrient requirements of pigs. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Australian Meat and Livestock Corporation. 1989. The Aus-Meat Standard Carcase Definition. AMLC, Sydney. (Mimeograph).Google Scholar
Diestre, A. and Kempster, A. J. 1985. The estimation of pig carcass composition from different measurements with special reference to classification and grading. Animal Production 41:383391.Google Scholar
Ellis, M., Smith, W. C., Henderson, R., Whittemore, C. T. and Laird, R. 1983. Comparative performance and body composition of control and selection line Large White pigs. 2. Feeding to appetite for a fixed time. Animal Production 36: 407413.Google Scholar
Elsley, F. W. H., McDonald, I. and Fowler, V. R. 1964. The effect of plane of nutrition on the carcasses of pigs and lambs when variations in fat content are excluded. Animal Production 6:141154.Google Scholar
Evans, D. G. and Kempster, A. J. 1979a. A comparison of different predictors of the lean content of pig carcasses. 2. Predictors for use in population studies and experiments. Animal Production 28: 97108.Google Scholar
Evans, D. G. and Kempster, A. J. 1979b. The effects of genotype, sex and feeding regimen on pig carcass development. 1. Primary components, tissues and joints. Journal of Agricultural Science, Cambridge 93: 339347.CrossRefGoogle Scholar
Evans, D. G. and 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
Fortin, A., Wood, J. D. and Whelehan, O. P. 1987. Breed and sex effects on the development, distribution of muscle, fat and bone, and the partition of fat in pigs. Journal of Agricultural Science, Cambridge 108:141153.CrossRefGoogle Scholar
Giles, L. R., Murison, R. D. and Wilson, B. R. 1981. Backfat studies in growing pigs. 1. Influence of energy intake on growth and carcass measurements at varying live weights. Animal Production 32: 3946.Google Scholar
Henderson, R., Whittemore, C. T., Ellis, M., Smith, W. C. and Laird, R. 1982. Effects of index selection at bacon weight on early growth rate and body composition in Large White pigs. Animal Production 35: 8185.Google Scholar
Henderson, R., Whittemore, C. T., Ellis, M., Smith, W. C., Laird, R. and Phillips, P. 1983. Comparative performance and body composition of control and selection line Large White pigs. 1. On a generous fixed feeding scale for a fixed time. Animal Production 36: 399405.Google Scholar
Kempster, A. J. and Evans, D. G. 1979a. A. comparison of different predictors of the lean content of pig carcasses. 1. Predictors for use in commercial classification and grading. Animal Production 28: 8796.Google Scholar
Kempster, A. J. and Evans, D. G. 1979b. The effects of genotype, sex and feeding regimen on pig carcass development. 2. Tissue weight distribution and fat partition between depots. Journal of Agricultural Science, Cambridge 93: 349358.Google Scholar
Meat and Livestock Commission. 1972. Combined test selection index revision 1972. Mimeograph 3/72. Meat and Livestock Commission, Bletchley.Google Scholar
Meat and Livestock Commission. 1983. Unusual fat distribution in pigs. Meat and Marketing Technical Note No. 1, pp. 57. Meat and Livestock Commission, Bletchley.Google Scholar
Wood, J. D. and Robinson, J. M. 1989. Prediction of carcass lean content from fat and muscle thickness measurements in Large White and Pietrain pigs. Livestock Production Science 21: 325332.CrossRefGoogle Scholar
Wood, J. D., Whelehan, O. P., Ellis, M., Smith, W. C. and Laird, R. 1983. Effects of selection for low backfat thickness in pigs on the sites of tissue deposition in the body. Animal Production 36: 389397.Google Scholar