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Growth and carcass composition of lambs of two breeds and their cross grazing ryegrass and clover swards

Published online by Cambridge University Press:  18 August 2016

J. M. Macfarlane ,
R. M. Lewis  and
G. C. Emmans
J. M. Macfarlane*
Affiliation:
Sustainable Livestock Systems, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK
R. M. Lewis
Affiliation:
Sustainable Livestock Systems, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, 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, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK
*
†E-mail: j.macfarlane@sac.ac.uk.
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Abstract

The effects of sward, breed type and sex on lamb growth and carcass composition were measured at two degrees of maturity in live weight. The three breed types were Scottish Blackface (no. = 60), Suffolk (no. = 59) and their reciprocal crosses (no. = 60). The lambs grazed swards of either ryegrass, clover or a mixed sward intended to contain both. The proportion of the mixed sward as clover was only 0.014. Each lamb was scanned using X-ray computed tomography to measure the weights of fat, lean and bone in the carcass at two proportions of mature body weight (0.30 and 0.45). Live weights were recorded weekly. Average daily gains (ADG) in live weight and carcass tissues were calculated for each lamb between the 0.30 and 0.45 stages of maturity.

At the 0-30 stage of maturity, breed type differences in carcass composition were small; the Scottish Blackface had 0.942 as much bone as the Suffolk lambs (P < 0.001), with the cross lambs intermediate. At the 0-45 stage of maturity, Scottish Blackface lambs had less fat (0.749 times as much; P < 0.001), more lean (1.065 times as much; P < 0.001) and more bone (1.055 times as much; P < 0-001) than did Suffolk lambs. The values for crossbred lambs were intermediate but closer to those of the Suffolk. Neither sward nor its interaction with breed type had any significant effect on carcass composition at either the 0-30 or 0-45 stage of maturity. The effect of sex on carcass composition was significant at the 0-45 stage of maturity when castrated male lambs had less fat (P < 0.001) and more lean (P < 0.001) than female lambs. There were breed type by sward interactions for ADG in live weight (P < 0.05), in carcass weight (P < 0.001), and in fat (P < 0.001) and bone weights (P < 0.05). The interactions were such that Suffolk lambs had higher growth rates than Scottish Blackface lambs on clover but not on ryegrass or the mixed sward. There were no significant differences between Suffolk and crossbred lambs in growth rates on any sward. In this, and in two other experiments, the extent to which growth rate declined as the nutritional environment became worse was greater (P < 0.05) in Suffolk than in Scottish Blackface lambs; that is, Suffolk lambs expressed greater environmental sensitivity than the Scottish Blackface.

Keywords

carcass compositionclovergrowthryegrasssheep
Type
Research Article
Information
Animal Science , Volume 79 , Issue 3 , December 2004 , pp. 387 - 396
Copyright
Copyright © British Society of Animal Science 2004

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References

Butterfield, R. M. and Thompson, J. M. 1983. Changes in body composition relative to weight and maturity of large and small strains of Australian Merino rams. 4. Fat depots and bones. Animal Production 37: 423–431.Google Scholar
Chakeredza, S., ter Meulen, U. and Ndlovu, L. R. 2001. Growth performance of weaner lambs offered maize stover supplemented with varying levels of maize and cottonseed meals. Livestock Production Science 73: 35–44.Google Scholar
Falconer, D. S. 1989. Introduction to quantitative genetics, third edition. Longman Scientific and Technical, England.Google Scholar
Freeman, G. H. 1973. Statistical methods for the analysis of genotype-environment interactions. Heredity 31: 339–354.Google Scholar
Friggens, N. C., Shanks, M., Kyriazakis, I., Oldham, J. D. and McClelland, T. H. 1997. The growth and development of nine European sheep breeds. 1. British breeds: Scottish Blackface, Welsh Mountain and Shetland. Animal Science 65: 409–426.CrossRefGoogle Scholar
Gaili, E. S. E. 1993. A comparison of body components of indigenous Saudi sheep breeds related to relative mature size and growth rate. Animal Production 57: 113–118.Google Scholar
Genstat 6 Committee. 2002. Genstat 6 (PC/Windows NT). Lawes Agricultural Trust, Rothamsted Experimental Station, Harpenden.Google Scholar
Jinks, J. L. and Connolly, V. 1973. Selection for specific and general response to environmental differences. Heredity 30: 33–40.Google Scholar
Kirton, A. H., Clarke, J. N. and Hickey, S. M. 1982. A comparison of the composition and carcass quality of Kelly and Russian castrate, ram, wether and ewe lambs. Proceedings of the New Zealand Society of Animal Production 42: 117–118.Google Scholar
Lewis, R. M., Emmans, G. C. and Simm, G. 2002. Effects of index selection on the carcass composition of sheep given either ad libitum or controlled amounts of food. Animal Science 75: 185–195.Google Scholar
Lewis, R. M., Emmans, G. C. and Simm, G. 2004a. Effects of index selection on the performance and carcass composition of sheep given foods of different protein concentrations ad libitum. Animal Science 78: 203–212.Google Scholar
Lewis, R. M., Emmans, G. C., Simm, G., Dingwall, D. S. and FitzSimons, J. 1998. A description of the growth of the sheep. Proceedings of the British Society of Animal Science, 1998, p. 47. Google Scholar
Lewis, R. M., Macfarlane, J. M., Simm, G. and Emmans, G. C. 2004b. Effects of food quality on growth and carcass composition in lambs of two breeds and their cross. Animal Science 78: 355–367.Google Scholar
McClelland, T. H., Bonatti, B. and Taylor, St C. S. 1976. Breed differences in body composition of equally mature sheep. Animal Production 23: 281–294.Google Scholar
McDonald, P., Edwards, R. A., Greenhalgh, J. F. D. and Morgan, C. A. 1995. Animal nutrition, fifth edition. Longman, Essex.Google Scholar
Macfarlane, J. M., Lewis, R. M. and Emmans, G. C. 2004. Effects of two dried forages, and a choice between them, on intake, growth and carcass composition in lambs of two breeds and their cross. Animal Science 78: 485–496.Google Scholar
Mahgoub, O., Lu, C. D. and Early, R. J. 2000. Effects of dietary energy density on feed intake, body weight gain and carcass chemical composition of Omani growing lambs. Small Ruminant Research 37: 35–42.CrossRefGoogle ScholarPubMed
Montossi, F., Hodgson, J., Morris, S. T., Risso, D. F. and Gordon, I. L. 2001. A comparative study of herbage intake, ingestive behaviour and diet selection, and effects of condensed tannins upon body and wool growth in lambs grazing Yorkshire fog (Holcus lanatus) and annual ryegrass (Lolium multiflorum) dominant swards. Journal of Agricultural Science, Cambridge 136: 241–251.Google Scholar
Nitter, G. 1978. Breed utilization for meat production in sheep. Animal Breeding Abstracts 46: 131–143.Google Scholar
Santos-Silva, J., Mendes, I. A. and Bessa, R. J. B. 2002. The effect of genotype, feeding system and slaughter weight on the quality of light lambs. 1. Growth, carcass composition and meat quality. Livestock Production Science 76: 17–25.Google 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., 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: 385–409.Google Scholar
Vipond, J. E., Swift, G., McClelland, T. H., Fitzsimons, J., Milne, J. A. and Hunter, E. A. 1993. A comparison of diploid and tetraploid perennial ryegrass and terraploid ryegrass/white clover swards under continuous sheep stocking at controlled sward heights. 2. Animal Production. Grass and Forage Science 48: 290–300.Google Scholar
Wood, J. D., Macfle, H. J. H., Pomeroy, R. W. and Twinn, D. J. 1980. Carcass composition in four sheep breeds: the importance of type of breed and stage of maturity. Animal Production 30: 135–152.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: 309–318.Google Scholar