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Effects of index selection on the carcass composition of sheep given either ad libitum or controlled amounts of food

Published online by Cambridge University Press:  18 August 2016

R. M. Lewis
Affiliation:
Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK
G. C. Emmans
Affiliation:
Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK
G. Simm
Affiliation:
Animal Biology Division, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK
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Abstract

Sheep of a line (S) selected on an index to increase lean weight and decrease fatness at an age, and a control line (C), were given a high quality food at different levels including ad libitum. Live performance was measured from about 21 to 114 kg live weight. The carcasses of each line were analysed for lean, fat and bone at three widely varying weights in both males and females. Level of feeding did not affect the extent to which S was superior to C in either the level of fatness in the carcass (0·86 as much) or the ratio of lean to fat (1·28 as much). The lean to bone ratio was slightly greater in S (1·028 of the value of C; P 0·05) and was higher on the lowest level of feeding compared with the two higher levels used (P 0·05 in one experiment on females and P 0·001 in another on males). On ad libitum feeding the S line grew 1·19 times as fast and was 1·17 times as efficient compared with C. These advantages to S decreased as level of feeding decreased to become virtually zero at the lowest level of feeding used, which allowed C to grow at only 0·53 of the rate seen on ad libitum feeding. On ad libitum feeding growth was well described by a Gompertz growth function of the form W = (Z/B) exp(-exp (G0 –B t)). The maximum growth rate is (Z/e). Line S had a value of Z that was 1·10 that of C averaged across the two sexes. A Spillman function W = W0 + (A-W0) (1-exp (-k F)) was used to describe weight, W, in terms of cumulative intake, F. It worked well for ad libitum feeding and for the two restricted regimes used. The value of the combined parameter (A k) varied across treatments in the same way as efficiency did.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 2002

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References

Abdullah, A. Y., Purchas, R. W. and Davies, A. S. 1998. Patterns of change with growth for muscularity and other composition characteristics of Southdown rams selected for high and low backfat depth. New Zealand Journal of Agricultural Research 41: 367376.CrossRefGoogle Scholar
Agricultural Research Council. 1980. The nutrient requirements of ruminants. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Beauchemin, K. A., McClelland, L. A., Jones, S. D. M. and Kozub, G. C. 1995. Effects of crude protein-content, protein degradability and energy concentration of the diet on growth and carcass characteristics of market lambs fed high concentrate diets. Canadian Journal of Animal Science 75: 387395.CrossRefGoogle Scholar
Cameron, N. D. and Bracken, J. 1992. Selection for carcass lean content in a terminal sire breed of sheep. Animal Production 54: 367377.Google Scholar
Cuthbertson, A., Harrington, G. and Smith, R. J. 1972. Tissue separation to assess beef and lamb variation. In Symposium on aspects of carcass evaluation. Proceedings of the British Society of Animal Production, 1972, pp. 113122.Google Scholar
Emmans, G. C. 1988. Genetic components of potential and actual growth. In Animal breeding opportunities (ed. Land, R. G. Bulfield, G. and Hill, W. G.) British Society of Animal Science occasional publication no. 12, pp. 153181.Google Scholar
Falconer, D. S. 1989. Introduction to quantitative genetics, third edition. Longman Scientific and Technical, England.Google Scholar
Fennessy, P. F., Greer, G. J., Bain, W. E. and Johnstone, P. D. 1993. Progeny test of ram lambs selected for low ultrasonic backfat thickness or high post-weaning growth-rate. Livestock Production Science 33: 105118.CrossRefGoogle Scholar
Freeman, G. H. 1973. Statistical methods for the analysis of genotype-environment interactions. Heredity 31: 339354.CrossRefGoogle ScholarPubMed
Genstat 5 Committee. 1998. Genstat 5 release 4·1(PC/ Windows NT). Lawes Agricultural Trust, Rothamsted Experimental Station, Harpenden.Google Scholar
Hall, D. G., Gilmour, A. R., Fogarty, N. M., Holst, P. J. and Hopkins, D. L. 2001. Growth and carcass composition of second-cross lambs. 1. Effect of sex and growth path on preand post-slaughter estimates of carcass composition. Australian Journal of Agricultural Research 52: 859867.CrossRefGoogle Scholar
Jinks, J. L. and Connolly, V. 1973. Selection for specific and general response to environmental differences. Heredity 30: 3340.CrossRefGoogle Scholar
Jones, H. E., Simm, G., Dingwall, W. S. and Lewis, R. M. 1999. Genetic relationships between visual and objective measures of carcass composition in crossbred lambs. Animal Science 69: 553561.CrossRefGoogle Scholar
Kempster, A. J. 1983. Carcass quality and its measurement in sheep. In Sheep production (ed. Haresign, W.), pp. 5974. Butterworths, London.Google Scholar
Lewis, R. M., Emmans, G. C., Dingwall, W. S. and Simm, G. 2002. A description of the growth of sheep and its genetic analysis. Animal Science 74: 5162.CrossRefGoogle Scholar
Lewis, R. M., Emmans, G. C., Simm, G., Dingwall, W. S. and Fitz Simons, J. 1998. A description of the growth of sheep. Proceedings of the British Society of Animal Science, 1998, p. 47.CrossRefGoogle Scholar
Lewis, R. M., Simm, G., Dingwall, W. S. and Murphy, S. V. 1996. Selection for lean growth in terminal sire sheep to produce leaner crossbred progeny. Animal Science 63: 133142.CrossRefGoogle Scholar
McClelland, T. H., Bonatti, B. and Taylor, St C. S. 1976. Breed differences in body composition of equally mature sheep. Animal Production 23: 281294.Google Scholar
Parks, J. R. 1970. Growth curves and the physiology of growth. American Journal of Physiology 219: 837839.CrossRefGoogle ScholarPubMed
Parks, J. R. 1982. A theory of feeding and growth of animals. Springer Verlag, Berlin.CrossRefGoogle Scholar
Simm, G. 1987. Carcass evaluation in sheep breeding programmes. In New techniques in sheep production (ed. Marai, I. F. M. and Owen, J. B.), pp. 125144. Butterworths, London.CrossRefGoogle Scholar
Simm, G. and Dingwall, W. S. 1989. Selection indices for lean meat production in sheep. Livestock Production Science 21: 223233.CrossRefGoogle Scholar
Simm, G., Lewis, R. M., Grundy, B. and Dingwall, W. S. 2002. Responses to selection for lean growth in sheep. Animal Science 74: 3950.CrossRefGoogle Scholar
Simm, G. and Murphy, S. V. 1996. The effects of selection for lean growth in Suffolk sires on the saleable meat yield of their crossbred progeny. Animal Science 62: 255263.CrossRefGoogle Scholar
Snedecor, G. W. and Cochran, W. G. 1980. Statistical methods; seventh edition. Iowa State University Press, Ames, IA.Google Scholar
Spillman, W. J. and Lang, E. 1924. The law of diminishing increment. World, Yonkers.Google Scholar
Taylor, St C. S., Murray, J. I. and Thonney, M. L. 1989. Breed and sex differences among equally mature sheep and goats. 4. Carcass muscle, fat and bone. Animal Production 49: 385409.Google Scholar
Thomas, P. C., Robertson, S., Chamberlain, D. G., Livingstone, R. M., Garthwaite, P. H., Dewey, P. J. S., Smart, R. and Whyte, C. 1988. Predicting the metabolizable energy (ME) content of compound feeds for ruminants. In Recent advances in animal nutrition (ed. W. Haresign and D. Cole, J. A.), pp. 127146. Butterworths, London.Google Scholar
Thompson, J. M., Butterfield, R. M. and Perry, D. 1985. Food intake, growth and body composition in Australian Merino sheep selected for high and low weaning weight. 2. Chemical and dissectible body composition. Animal Production 40: 7184.Google Scholar
Winsor, C. P. 1932. The Gompertz curve as a growth curve. Proceedings of the National Academy of Sciences of the United States of America 18: 1–8.Google ScholarPubMed
Woodward, J. and Wheelock, V. 1990. Consumer attitudes to fat in meat. In Reducing fat in meat animals (ed. Wood, J. D. and Fisher, A. V.), pp. 66100. Elsevier, London.Google Scholar
Wylie, A. R. G., Chestnutt, D. M. B. and Kilpatrick, D. J. 1997. Growth and carcass characteristics of heavy slaughter weight lambs: effects of sire breed and sex of lamb and relationships to serum metabolites and IGF–1. Animal Science 64: 309318.CrossRefGoogle Scholar