Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-30T21:22:53.494Z Has data issue: false hasContentIssue false

Quantitative analysis of methionine and cysteine requirements for wool production of sheep

Published online by Cambridge University Press:  18 August 2016

Get access

Abstract

The conventional system of estimating metabolizable protein requirement is unsuitable for defining amino acid requirements because nitrogen loss cannot be converted to amino acid loss, and because there is a lack of data on the utilization efficiencies of individual amino acids for various productive purposes. Therefore, we are proposing an alternative approach. In this review, we use methionine (Met) and cysteine (Cys) for wool production in sheep as examples, and define requirement as retention in both body and wool protein, plus the amount of obligatory oxidation that accompanies the retention. The requirements are expressed in terms of the net absorption. Mathematical models for the calculation of the requirements of both amino acids are established based on the level of absorption, endogenous contribution from body protein breakdown, oxidation rates and the amino acid composition of body and wool proteins. The flows and oxidation of Met and Cys, and Cys synthesis de novo as well are quantified using their plasma kinetics data. Wool growth rate is predicted from the amount of the amino acid available for protein retention and the partition ratio to wool growth. The estimated requirements for Met and Cys absorption for Merino sheep at maintenance are 0·45 to 0·75 g/day and 0·52 to 0·63 g/day depending on the live weight of the sheep. When wool growth rate increases to 10 g/day, the requirements increase to 0·91 to 1·24 g/day and 1·97 to 2·02 g/day respectively. The utilization efficiency for protein retention varies with the level of absorption, and is 0·02 to 0·55 for Met, and 0·09 to 0·55 for Cys. The model shows that wool growth rate is restricted by the lack of Cys supplied in conventional diets and is very sensitive to changes in oxidation of the amino acids.

Type
Ruminant nutrition, behaviour and production
Copyright
Copyright © British Society of Animal Science 2000

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

Agricultural and Food Research Council. 1993. Energy and protein requirements of ruminants. An advisory manual prepared by the AFRC Technical Committee on Responses to Nutrients. CAB International, Wallingford, UK.Google Scholar
Agricultural Research Council. 1984. The nutrient requirements of ruminant livestock. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Benevenga, N. J., Radcliffe, B. C. and Egan, A. R. 1983. Tissue metabolism of methionine in sheep. Australian Journal of Biological Science 36: 475485.Google Scholar
Black, J. L., Campbell, R. G., Williams, I. H., James, K. J. and Davies, G. T. 1986. Simulation of energy and amino acid utilization in the pig. Research and Development in Agriculture 3: 121145.Google Scholar
Black, J. L., Robards, G. E. and Thomas, R. 1973. Effects of protein and energy intakes on the wool growth of Merino wethers. Australian Journal of Agricultural Research 24: 399412.Google Scholar
Cooper, A. J. L. 1983. Biochemistry of sulphur-containing amino acids. Annual Review of Biochemistry 52: 187222.CrossRefGoogle Scholar
Downes, A. M., Sharry, L. F. and Till, A. R. 1964. The fate of intradermal doses of labelled amino acids in sheep. Australian Journal of Biological Sciences 17: 945959.CrossRefGoogle Scholar
Egan, A. R., Benevenga, N. J. and Radcliff, B. C. 1984. The metabolism of S-amino acids in sheep. Proceedings of a symposium held at University of Western Australia (ed. Baker, S.K., Gawthorne, J.M., Mackintosh, J. B. and Purser, D. B.), pp. 241252. School of Agriculture of the University of Western Australia, Perth.Google Scholar
Fennessy, P., Egan, A. and Radcliff, B. 1978. Effect of methionine infusion on ovine methionine and cysteine metabolism. Proceedings of the Nutrition Society of Australia 3: 74.Google Scholar
Freer, M., Moore, A. D. and Donnelly, J. R. 1997. GRAZPLAN: decision support systems for Australian grazing enterprises. II. The animal biology model for feed intake, production and reproduction and the GrazFeed DSS. Agricultural Systems 54: 77126.Google Scholar
Galbraith, H. 1998. Nutritional and hormonal regulation of hair follicle growth and development. Proceedings of the Nutrition Society 57: 195205.Google Scholar
Gill, M. and Ulyatt, M. J. 1979. The metabolism of methionine in silage-fed sheep. British Journal of Nutrition 41: 605609.Google Scholar
Harris, P. M., Lee, J., Sinclair, B. R. and Treloar, B. P. 1994a. The effect of whole body cysteine supplementation on cysteine utilization by the skin of a well-fed sheep. Proceedings of the New Zealand Society of Animal Production, 1994, pp. 139142.Google Scholar
Harris, P. M., Lee, J., Sinclair, B. R., Treloar, B. P. and Gurnsey, M. P. 1994b. Effect of food intake on energy and protein metabolism in the skin of Romney sheep. British Journal of Nutrition 71: 647660.Google Scholar
Harris, P. M., Sinclair, B. R., Treloar, B. P. and Lee, J. 1997. Short-term changes in whole body and skin sulfur amino acid metabolism of sheep in response to supplementary cysteine. Australian Journal of Agricultural Research 48: 137146.Google Scholar
Lee, G. J. and Williams, A. J. 1993. Relationship of feed intake with cystine availability and wool growth in Merino wethers. Australian Journal of Agricultural Research 44: 973991.CrossRefGoogle Scholar
Lee, J., Harris, P. M., Sinclair, B. R. and Treloar, B. P. 1993. Sulfur amino acid metabolism and protein synthesis in young sheep fed ryegrass pasture and two lotus cultivars containing condensed tannin. Australian Journal of Agricultural Research 46: 15871600.CrossRefGoogle Scholar
Liu, S. M. 1995. The use of blood metabolites as indices in the assessment of protein status in ruminants. Ph.D. thesis, Faculty of Science of the University of Aberdeen, Aberdeen.Google Scholar
Liu, S. M., Lobley, G. E., MacLeod, N. A., Kyle, D. J., Chen, X. B. and Ørskov, E. R. 1995. Effects of long-term protein excess or deficiency on whole-body protein turnover in sheep nourished by intragastric infusion of nutrients. British Journal of Nutrition 73: 829839.Google Scholar
Liu, S. M., Mata, G., Figlimoneni, S., Powell, B. C., Nesci, A. and Masters, D. G. 2000. Transsulphuration, protein synthesis rate and follicle mRNA in the skin of young Merino sheep in response to infusions of methionine and serine. British Journal of Nutrition 83: 401409.Google Scholar
Lobley, G. E., Connell, A. and Revell, D. 1996. The importance of transmethylation reactions to methionine metabolism in sheep: effects of supplementation with creatine and choline. British Journal of Nutrition 75: 4756.Google Scholar
McNabb, W. C., Waghorn, G. C., Barry, T. N. and Shelton, I. D. 1993. The effect of condensed tannins in Lotus pedunculatus on the digestion and metabolism of methionine, cystine and inorganic sulphur in sheep. British Journal of Nutrition 70: 647661.Google Scholar
MacRae, J. C., Walker, A., Brown, D. and Lobley, G. E. 1993. Accretion of total protein and individual amino acids by organs and tissues of growing lambs and the ability of nitrogen balance techniques to quantitate protein retention. Animal Production 57: 237245.Google Scholar
Martin, C., Bernard, L. and Michalet-Doreau, B. 1996. Influence of sampling time and diet on amino acid composition of protozoal and bacterial fractions from bovine ruminal contents. Journal of Animal Science 74: 11571163.CrossRefGoogle ScholarPubMed
Masters, D. G., Mata, G., Liu, S. M. and Peterson, A. D. 1998. Influence of liveweight, liveweight change, and diet on wool growth, staple strength, and fibre diameter in young sheep. Australian Journal of Agricultural Research 49: 269277.Google Scholar
Mata, G., Masters, D. G., Buscall, D., Street, K. and Schlink, A. C. 1995. Responses in wool growth, liveweight, glutathione and amino acids, in Merino wethers fed increasing amounts of methionine protected from degradation in the rumen. Australian Journal of Agricultural Research 46: 11891204.Google Scholar
Pisulewski, P. M. and Buttery, P. J. 1985. The effect of increasing methionine supply on the methionine conversion to cyst(e)ine in sheep. British Journal of Nutrition 54: 121129.Google Scholar
Radcliffe, B. C. and Egan, A. R. 1974. A survey of methionine adenosyltransferase and cystathionine r-lyase activities in ruminant tissues. Australian Journal of Biological Sciences 27: 465471.Google Scholar
Radcliffe, B. C. and Egan, A. R. 1978. The effect of diet and of methionine loading on activity of enzymes in the transsulphuration pathway in sheep. Australian Journal of Google Scholar
Reis, P. J. 1979. Effects of amino acids on the growth and properties of wool. In Physiological and environmental limitations to wool growth (ed. Black, J. L. and Reis, P. J.), pp. 223242. University of New England Publishing Unit, Armidale.Google Scholar
Reis, P. J., Tunks, D. A. and Munro, S. G. 1990. Effects of the infusion of amino acids into the abomasum of sheep, with emphasis on the relative value of methionine, cysteine and homocysteine for wool growth. Journal of Agricultural Science, Cambridge 114: 5968.Google Scholar
Storm, E. and Ærskov, E. R. 1983. The nutritive value of rumen micro-organisms in ruminants. 1. Large-scale isolation and chemical composition of rumen micro-organisms. British Journal of Nutrition 50: 463470.Google Scholar
Sun, Y. N., Lee, J., Harris, P. M., Sinclair, B. R., Shelton, I. D., Blair, H. T. and McCutcheon, S. N. 1994. Nitrogen and sulfur metabolism and plasma thyroid hormone concentrations in fleeceweight-selected and control Romney sheep at two ambient temperatures. Australian Journal of Agricultural Research 45: 339354.Google Scholar
Wang, Y. X., Waghorn, G. C., Barry, T. N. and Shelton, I. D. 1994. The effect of condensed tannins in Lotus pedunculatus on plasma metabolism of methionine, cystine and inorganic sulphur by sheep. British Journal of Nutrition 72: 923935.Google Scholar
Waterlow, J. C., Garlick, P. J. and Millward, D. J. 1978. Protein turnover in mammalian tissues and in whole-body. North-Holland Publishing Company, Amsterdam.Google Scholar
Williams, A. 1995. Wool growth. In Australian sheep and wool handbook (ed. Cottle, D. J.), pp. 224242. Inkata Press, Melbourne.Google Scholar
Williams, A. J. 1976. Metabolism of cystine by Merino sheep genetically different in wool production. 4. Rates of entry of cystine into plasma, measured with a single intravenous injection of L-[35S]cystine, and the subsequent incorporation of 35S into wool fibres. Australian Journal of Biological Sciences 29: 513524.Google Scholar
Williams, A. J., Leng, R. A. and Stephenson, S. K. 1972. Metabolism of cystine by Merino sheep genetically different in wool production. 1. Comparison of the entry rates of cystine in sheep from flocks selectively bred for high and low fleece weight. Australian Journal of Biological Sciences 25: 12591268.Google Scholar
Williams, A. J., Murison, R. and Padgett, J. 1988. Metabolism of sulphur-containing amino acids by pregnant Merino ewes. Australian Journal of Biological Sciences 41: 247259.Google Scholar
Zebrowska, T., Zebrowska, H. and Pajak, J. 1987. Efficiency of utilization of absorbed amino acids in growing sheep. In Protein metabolism and nutrition, Proceedings of the fifth international symposium on protein metabolism and nutrition (European Association for Animal Production, publication no. 35), pp. 83. EAAP, Rostock.Google Scholar