Hostname: page-component-76fb5796d-45l2p Total loading time: 0 Render date: 2024-04-27T03:25:32.214Z Has data issue: false hasContentIssue false

The effects of dietary protein level during food restriction on carcass and non-carcass components, digestibility and subsequent compensatory growth in lambs

Published online by Cambridge University Press:  02 September 2010

G. R. Iason
Affiliation:
Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB9 2QL
A. R. Mantecon
Affiliation:
Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB9 2QL
Get access

Abstract

The effect of proportion of dietary rumen non-degradable protein during food restriction on the weight of components of the digestive tract, carcass and subsequent growth was investigated in 37 Scottish Blackface wether lambs (initial live weight, 25 kg). Lambs were given individually ad libitum for 4 weeks a complete pelleted diet containing 150 g/kg white fish-meal (HP, 10·4 MJ metabolizable energy (ME) per kg dry matter (DM), 195 g crude protein (CP) per kg DM). Seven lambs were then slaughtered and 15 were switched to a diet containing no white fish-meal (LP, 10·4 MJ ME per kg DM, 122 g CP per kg DM) offered at 18 g DM per kg M per day, i.e. sufficient to maintain constant live weight. A further 15 continued to receive the HP diet at the same rate as the lambs given LP. After 6 and 12 weeks, five lambs on each diet were slaughtered. At 12 weeks the remainder received the HP diet ad libitum for a further 7 weeks before slaughter. During food restriction on both diets, the proportion of live weight formed by the carcass, the dissected components and the chemical composition remained the same as in the initial slaughter group. The relative weight of the non-carcass components fell during food restriction on both diets. There was a significant (P < 0·05) interaction between slaughter date and dietary treatment for reticulo-rumen weight as a proportion of empty body weight (EBM); it was smaller in lambs on the HP diet after 12 weeks of restriction (HP: 0·022, LP: 0·026). A similar pattern was observed for the small intestine and the total digestive tract. During the 7 weeks of realimentation, lambs previously on HP and LP diets had similar intakes (1343 and 1208 g DM per day) and digestive tract components, body components and chemical composition of carcass and non-carcass components were all unaffected by previous treatment. The apparent digestibility of CP of the HP diet was greater than that of the LP diet although it was overall less degradable in the rumen. When both groups of lambs were realimented on the HP diet, there were no differences in the apparent digestibility of any of the dietary components. A high dietary protein: energy ratio during restriction reduced the weight of some of the components of the digestive tract but did not significantly affect carcass composition. The effect did not persist following realimentation and did not significantly influence subsequent performance.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1993

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

Asplund, J. M., Hedrick, H. B. and Haugebak, C. D. 1975. Performance, digestibility and 40K levels in lambs during compensation for feed restriction. Journal of Animal Science 40: 138143.CrossRefGoogle Scholar
Chowdhury, S. A., Ørskov, E. R., Hovell, F. D. DeB. and Mollison, G. 1991. Protein utilization during energy undernutrition in the ruminant. Proceedings of the sixth international symposium on protein metabolism and nutrition, Herning, Denmark, pp. 154157.Google Scholar
Doney, J. M., Milne, J. A., Maxwell, T. J., Sibbald, A. M. and Smith, A. D. M. 1988. The effects of live weight at weaning on growth rate and carcass composition at different stages of maturity in Scottish Blackface lambs fed on two different diets. Animal Production 47: 401409..Google Scholar
Fell, B. F. and Weekes, T. E. C. 1975. Food intake as a mediator of adaptation in the ruminal epithelium. In Digestion and metabolism in the ruminant (ed. MacDonald, I. W. and Warner, A. C. I.), Proceedings of the fourth international symposium on ruminant physiology, Sydney, Australia, pp. 101118. University of New England, Armidale.Google Scholar
Fattet, I., Hovell, F. D. DeB., Ørskov, E. R., Kyle, D. J., Pennie, K. and Smart, R. I. 1984. Undernutrition in sheep. The effect of supplementation with protein on protein accretion. British Journal of Nutrition 52: 561574.CrossRefGoogle ScholarPubMed
Hovell, F. D. DeB., Ørskov, E. R., Kyle, D. J. and MacLeod, N. A. 1987. Undernutrition in sheep. Nitrogen repletion by N-depleted sheep. British Journal of Nutrition 57: 7788.CrossRefGoogle ScholarPubMed
Iason, G. R., Mantecon, A. R., Milne, J. A., Sim, D. A., Smith, A. D. M. and White, I. R. 1992. The effect of pattern of food supply on performance, compensatory growth and carcass composition of Beulah and Welsh Mountain lambs. Animal Production 54: 235241.Google Scholar
Lawes Agricultural Trust. 1984. GENSTAT V, mark 4.04. Rothamsted Experimental Station, Harpenden.Google Scholar
Murray, D. M. and Slezacek, O. 1980. Growth rate effects on some offal components of sheep. Journal of Agricultural Science, Cambridge 95: 241250.CrossRefGoogle Scholar
Murray, D. M. and Slezacek, O. 1988a. The effect of weight stasis on the dissected carcass composition of crossbred sheep. Australian Journal of Agricultural Research 39: 645651.CrossRefGoogle Scholar
Murray, D. M. and Slezacek, O. 1988b. The effect of weight stasis on the non-carcass components of crossbred sheep. Australian Journal of Agricultural Research 39: 653658.CrossRefGoogle Scholar
O'Donovan, P. B. 1984. Compensatory gain in cattle and sheep. Nutrition Abstracts and Reviews Series B 54: 389410.Google Scholar
Ryan, W. J. 1990. Compensatory growth in cattle and sheep. Nutrition Abstracts and Reviews Series B, 60: 653664.Google Scholar
Snedecor, G. W. and Cochran, W. G. 1980. Statistical methods. Iowa State University Press, Ames, Iowa.Google Scholar
Thornton, R. F., Hood, R. L., Jones, P. N. and Re, V. M. 1979. Compensatory growth in sheep. Australian Journal of Agricultural Research 30: 135151.CrossRefGoogle Scholar
Turgeon, O. A., Brink, D. R., Bartle, S. J., Klopfenstein, T. J. and Ferrell, C. L. 1986. Effects of growth rate and compensatory growth on body composition in lambs. Journal of Animal Science 63: 770780.CrossRefGoogle ScholarPubMed
Vipond, J. E., King, M. E., Ørskov, E. R. and Wetherill, G. Z. 1989. Effects of fish-meal supplementation on performance of overfat lambs fed on barley straw to reduce carcass fatness. Animal Production 48: 131138.CrossRefGoogle Scholar
Wilson, P. N. and Osbourn, D. F. 1960. Compensatory growth after undernutrition in mammals and birds. Biological Reviews 35: 324363.CrossRefGoogle ScholarPubMed