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Effects of molybdenum concentration in fresh herbage, hay and semi-purified diets on the copper metabolism of sheep

Published online by Cambridge University Press:  27 March 2009

N. F. Suttle
Affiliation:
Moredun Research Institute, 408 Gilmerton Road, Edinburgh, EH17 1JH

Summary

In Expt 1, four groups of seven hypocupraemic ewes were repleted with a semipurified diet containing 7·2 mg Cu, 3·5 gS and 0·5, 2·5, 4·5 or 8·5 mg Mo/kg D.M. as ammonium molybdate for 65 days. The first increment in Mo caused the largest reduction in plasma Cu repletion and the second completely inhibited repletion but the final increment led to a partial recovery. The highest Mo level caused marked increases in plasma Mo and reduced rumen sulphide concentrations.

In Expt 2, five groups of four hypocupraemic ewes were repleted with hays containing 7–8 mg Cu, 3–3·4 g S and 0·4, 2·8, 4·3, 14·2 or 18·7 mg Mo/kg D.M. for 21 days. The hays were made in June from pasture sprayed earlier with 0–800 g Mo/ha as sodium molybdate. Qualitatively the changes in plasma Cu distribution and Mo content showed the same curvature with increases in dietary Mo as those in Expt 1.

In Expt 3, four groups of five hypocupraemic ewes were repleted on pastures which had received a spring foliar dressing of 0–800 g Mo/ha. Herbage in the four plots was grazed in July, when it contained 0·7, 3·5, 5·9 or 12·4 mg Mo, 6'4 mg Cu and 2·7 g S/kg D.M. and again in September. Quadratic responses to Mo were demonstrated on both occasions, but, for a given Mo level, responses in caeruloplasmin synthesis were much lower than in Expt 2.

It is concluded that Cu absorption is inhibited most by 4–6 mg Mo/kg D.M. and that inhibition of S2- production at higher Mo levels may give rise to a recovery in Cu absorption. Semi-purified diets give responses which lie roughly between those for fresh herbage and hay.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1983

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References

Agricultural Research Council (1980). The Nutrient Requirements of Ruminant Livestock, pp. 221234. Farnham Royal, Slough: Commonwealth Agricultural Bureaux.Google Scholar
Alexander, R. H. & McGowan, M. (1966). The routine determination of in vitro digestibility of organic matter in forages. Journal of the British Grassland Society 21, 140147.CrossRefGoogle Scholar
Bingley, J. B. (1963). Determination of molybdenum in biological material with dithiol: control of copper interference. Journal of Agricultural and Food Chemistry 11, 130131.CrossRefGoogle Scholar
Dick, A. T., Dewey, D. W. & Gawthorne, J. M. (1975). Thiomolybdates and the copper–molybenum–sulphur interaction in ruminant nutrition. Journal of Agricultural Science, Cambridge 85, 567–568.CrossRefGoogle Scholar
Ferguson, W. S., Lewis, A. H. & Watson, S. J. (1943). The teart pastures of Somerset. 1. The cause and cure of teartness. Journal of Agricultural Science, Cambridge 33, 4449.Google Scholar
Gawthorne, J. M. & Nader, C. J. (1976). The effect of molybdenum on the conversion of sulphate to sulphide and microbial protein-sulphur in the rumen of sheep. British Journal of Nutrition 3, 1123.CrossRefGoogle Scholar
Hartmans, J. & Bosman, M. S. M. (1970). Differences in the copper status of grazed and housed cattle and their biochemical backgrounds. Proceedings of First International Symposium of Trace Element Metabolism in Animals (ed. Mills, C. F.), pp. 362366. Edinburgh: E. and S. Livingstone.Google Scholar
Huisingh, J. & Matrone, G. (1972). Copper-molybdenum interactions with the sulphate-reducing system in rumen micro-organisms. Proceedings of the Society for Experimental Biology and Medicine 139, 518521.CrossRefGoogle Scholar
Langlands, J. P., Bowles, J. E., Donald, G. E., Smith, A. J. & Paull, D. R. (1981). Copper status of sheep grazing pastures fertilized with sulphur and molybdenum. Australian Journal of Agricultural Research 32, 479486.CrossRefGoogle Scholar
McDonald, I., Mills, C. F., Dalgarno, A. C. & Simpson, A. M. (1979). Rates of loss of hepatic copper during copper-depletion of cattle. Proceedings of the Nutrition Society 38, 59 A.Google ScholarPubMed
MacRae, J. C. (1979). Protein metabolism. In The Management and Diseases of Sheep, pp. 183200. Farnham Royal, Slough: The British Council and the Commonwealth Agricultural Bureaux.Google Scholar
Mason, J., Lamand, M., Tressol, J. C. & Lab, C. (1978). The influence of dietary sulphur, molybdate and copper on the absorption, excretion and plasma fraction levels of 99Mo in sheep. Annales de Recherche Vétérinaire 9, 577586.Google Scholar
Quin, B. F. & Woods, P. H. (1979). Automated catalytic method for the routine determination of molybdenum in plant material. Analyst, London 104, 552559.CrossRefGoogle Scholar
Smith, B. S. W. & Wright, H. (1974). Improved manual and automatic procedures for estimation of caeruloplasmin oxidase activity. Clinica Ohimica Acta 50, 359366.CrossRefGoogle Scholar
Suttle, N. F. (1974 a). A technique for measuring the biological availability of copper to sheep using hypocupraemic ewes. British Journal of Nutrition 32, 395405.CrossRefGoogle ScholarPubMed
Suttle, N. F. (1974 b). Effects of organic and inorganic sulphur on the availability of dietary copper to sheep. British Journal of Nutrition 32, 559568.CrossRefGoogle ScholarPubMed
Suttle, N. F. (1975). The roles of organic sulphur in the copper–molybdenum–S relationship in ruminant nutrition. British Journal of Nutrition 34, 411420.CrossRefGoogle Scholar
Suttle, N. F. (1979). Effects of sulphur and molybdenum on the absorption of copper from forage crops by ruminants. Proceedings of Symposium on Sulphur in Forages, Wexford, Ireland (Brogan, J. C.), pp. 197211. Dublin: An Foras Taluntais.Google Scholar
Suttle, N. F. (1980). Some preliminary observations on the absorbability of copper in fresh and conserved grass to sheep. Proceedings of the Nutrition Society 39, 63 A.Google Scholar
Suttle, N. F. (1981). Effectiveness of orally administered cupric oxide needles in alleviating hypocupraemia in sheep and cattle. Veterinary Record 108, 417–410.Google Scholar
Suttle, N. F., Abrahams, P. W. & Thornton, I. (1982). The importance of soil type and dietary sulphur in the impairment of copper absorption in sheep which ingest soil. Proceedings of the Nutrition Society 41, 83 A.Google Scholar
Suttle, N. F. & Field, A. C. (1983). Some effects of thiomolybdates on the copper and molybdenum metabolism of sheep. Journal of Comparative Pathology (in the Press).CrossRefGoogle Scholar
Suttle, N. F. & McLauchlan, M. (1976). Predicting the effects of dietary molybdenum and sulphur on the availability of copper to ruminants. Proceedings of the Nutrition Society 35, 22 A.Google ScholarPubMed
Suttle, N. F. & Price, J. (1976). The potential toxicity of animal excreta to sheep. Animal Production 23, 233241.Google Scholar
Whitelaw, A., Armstrong, R. H., Evans, C. C. & Fawcett, A. R. (1979). A study of the effect of copper deficiency in Scottish Blackface lambs on improved hill pasture. Veterinary Record 104, 455460.CrossRefGoogle ScholarPubMed
Woolliams, J. A., Suttle, N. F., Wiener, G. & Field, A. C. (1981). Genetic and dietary factors in copper accumulation by sheep. Proceedings of Fourth international Symposium on Trace Element Metabolism in Man and Animals, Perth W. A. (ed. Gawthorne, J. C.), pp. 137139. Canberra: Australian Academy of Science.CrossRefGoogle Scholar