Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-24T09:10:47.774Z Has data issue: false hasContentIssue false

Effects of index selection on the performance and carcass composition of sheep given foods of different protein concentrations ad libitum

Published online by Cambridge University Press:  18 August 2016

R. M. Lewis*
Affiliation:
Sustainable Livestock Systems Group, Scottish Agricultural College, Penicuik, Midlothian EH26 0PH, UK Department of Animal and Poultry Sciences (0306), Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 USA
G. C. Emmans
Affiliation:
Sustainable Livestock Systems Group, Scottish Agricultural College, Penicuik, Midlothian EH26 0PH, UK
G. Simm
Affiliation:
Sustainable Livestock Systems Group, Scottish Agricultural College, Penicuik, Midlothian EH26 0PH, UK
*
Get access

Abstract

Sheep of a line selected on an index to increase carcass lean content at 150 days of age (selected (S); no. = 90), and an unselected control line (control (C); no. = 90), were given ad libitum foods of three different protein concentrations (192, 141 and 120 g/kg dry matter). Growth 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 protein did not affect the extent to which S was superior to C in the content of fat (0.86 as much) or lean (1.08 as much) in the carcass. The fat concentration of the carcass increased, and the lean concentration decreased, as dietary protein concentration was reduced (P < 0.01). On the highest level of protein used, the S line grew 1.17 times as fast and was 1.10 times as efficient compared with C. The extent to which growth rate in S exceeded that in C was greater on the highest level of protein used (92.3 g/day) than on the two lower protein diets (26.4 g/day). The difference of 65.9 (s.e. 18.4) g/day was significant (P < 0.01). On the diet of highest protein concentration, growth was well described by a Gompertz function. The S line had an estimated maximum growth rate 1.25 times that of the C when averaged across males and females. A Spillman function was used to describe weight in terms of cumulative intake. It worked well for all three levels of dietary protein concentration. S sheep performed better than unselected sheep on foods differing in protein concentration and over a wide range of live weights, suggesting benefits are likely within the diverse farming environments found in practice.

Type
Breeding and genetics
Copyright
Copyright © British Society of Animal Science 2004

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

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-concentration, 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
Emmans, G. C. 1988. Genetic components of potential and actual growth. In Animal breeding opportunities (ed. R. B. Land, G. Bulfield and Hill, W. G.), British Society of Animal Science occasional publication no. 12, pp. 153181.Google Scholar
Emmans, G. C. 1989. The growth of turkeys. In Recent advances in turkey science (ed. Nixey, C. and Grey, T. C.), Poultry Science symposium no. 21, pp. 135166. Butterworths, London.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
Fluharty, F. L. and McClure, K. E. 1997. Effects of dietary energy intake and protein concentration on performance and visceral organ mass in lambs. Journal of Animal Science 75: 604610.CrossRefGoogle ScholarPubMed
Genstat 5 Committee. 1998. Genstat 5 release 4.1 (PC/ Windows NT). Lawes Agricultural Trust, Rothamsted Experimental Station, Harpenden.Google Scholar
Griminger, P. and Scott, H. M. 1959. Growth rate and lysine requirement of the chick. Journal of Nutrition 68: 429442.CrossRefGoogle ScholarPubMed
Haddad, S. G., Nasr, R. E. and Muwalla, M. M. 2001. Optimum dietary crude protein level for finishing Awassi lambs. Small Ruminant Research 39: 4146.CrossRefGoogle ScholarPubMed
Hammond, J. 1932. Growth and development of mutton qualities in the sheep. Oliver and Boyd, Edinburgh.Google 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
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: 337346.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: 165173.Google Scholar
Lewis, R. M., Emmans, G. C., Dingwall, W. S. and Simm, G. 2002a. A description of the growth of sheep and its genetic analysis. Animal Science 74: 5162.CrossRefGoogle Scholar
Lewis, R. M., Emmans, G. C. and Simm, G. 2002b. Effects of index selection on the carcass composition of sheep given either ad libitum or controlled amounts of food. Animal Science 75: 185195.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
National Research Council. 1985. Nutrient requirements of sheep, sixth revised edition. National Academy Press, Washington, DC.Google Scholar
Parks, J. R. 1982. A theory of feeding and growth of animals. Springer Verlag, Berlin.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
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) concentration of compound feeds for ruminants. In Recent advances in animal nutrition (ed. Haresign, W. and Cole, D. 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
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