Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-03T02:05:07.371Z Has data issue: false hasContentIssue false

The effect of site and quantity on the extent of absorption of Mg infused into the gastro-intestinal tract of sheep

Published online by Cambridge University Press:  27 March 2009

A. C. Field
Affiliation:
Moredun Research Institute, Edinburgh, EH17 7JH
C. S. Munro
Affiliation:
Moredun Research Institute, Edinburgh, EH17 7JH

Summary

Balance trials were carried out in which different amounts of Mg (0·44–2·9 g/day) were infused alternatively into the rumen and into the omasum, abomasum or duodenum of sheep consuming a low Mg diet (0·2 g Mg/kg D.M.). Absorption from the region between the infusion sites was measured from the change in urinary excretion and apparent absorption caused by changing the site of infusion.

Absorption was greater from a ruminal than from a comparable duodenal infusion. There was evidence, however, that the absorption mechanism within the stomach area was becoming saturated at the higher infusion rates in that the relationship between the amount absorbed and infused was curvilinear. The proportion of infused Mg which was absorbed from the stomach area fell from 0·61 to 0·14 as the infusion rate increased from 0·44 to 2·80 g/day.

The main site of absorption within the stomach area was the rumen; a small amount was absorbed from the omasum, but none from the abomasum. Positive differences between omasal and duodenal infusions were seen in plasma concentration at the two lowest and in urinary excretion at all infusion rates.

Increasing the amount of Mg infused into the duodenum caused an increase in plasma concentration and a linear increase in absorption.

When the ruminal and duodenal infusions were repeated with the sheep consuming hay, the results were similar but the proportion of infused Mg absorbed was reduced.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1977

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, Research Council (1965). The Nutrient Requirements of Farm Livestock. No. 2. Ruminants. London: A.R.C.Google Scholar
Ben-Ghedalia, D., Tagari, H., Zamwel, S. & Bondi, A. (1975). Solubility and net exchange of calcium, magnesium and phosphorus in digesta flowing along the gut of the sheep. British Journal of Nutrition 33, 8794.CrossRefGoogle ScholarPubMed
Care, A. D. & van't Klooster, A. T. (1965). In vivo transport of magnesium and other cations across the wall of the gastro-intestinal tract of sheep. Journal of Physiology, London 177, 174–91.CrossRefGoogle ScholarPubMed
Dixon, W. J. (1972). Biomedical Computing Programs, X – Series Supplement, p. 153. Berkeley: University of California Press.Google Scholar
Dobson, A. & Phillipson, A. T. (1958). The absorption of chloride ions from the reticulo-rumen sac. Journal of Physiology, London 150, 94104.CrossRefGoogle Scholar
Engelhardt, W.V. & Hauffe, R. (1975). Role of the omasum in absorption and secretion of water and electrolytes in sheep and goats. In Digestion and Metabolism in the Ruminant (ed. McDonald, I. W. and Warner, A. C. I.), pp. 216–30. Armidale: University of New England Press.Google Scholar
Field, A. C., McCallum, J. W. & Butler, E. J. (1958). Studies on magnesium in ruminant nutrition. Balance experiments on sheep with herbage from fields associated with lactation tetany and from control pastures. British Journal of Nutrition 12, 433–46.CrossRefGoogle ScholarPubMed
Field, A. C., Suttle, N. F. & Gunn, R. G. (1968). Seasonal changes in the composition and mineral content of the body of hill ewes. Journal of Agricultural Science, Cambridge 71, 303–10.Google Scholar
Field, A. C., Sykes, A. R. & Gunn, R. G. (1974). Effect of age and state of incisor dentition on faecal output of dry matter and on faecal and urinary output of nitrogen and minerals, of sheep grazing hill pastures. Journal of Agricultural Science, Cambridge 83, 151–60.Google Scholar
Martens, H., Harmeyer, J. & Beeves, G. (1976). In vitro studies on magnesium uptake by rumen epithelium using magnesium28. Nuclear Techniques in Animal Production and Health, pp. 261–8. Vienna, Austria: IAEA.Google Scholar
Robinson, R., Roughan, M. E. & Wagstaff, D. F. (1971). Measuring inorganic phosphate without using a reducing agent. Annals of Clinical Biochemistry 8, 168–70.Google Scholar
Rogers, P. A. M. & van't Klooster, A. T. (1969). Observations on the digestion and absorption of food along the gastro-intestinal tract of fistulated cows. 3. The fate of Na, K, Ca, Mg and P in the digesta. Mededelingen Landbouwhogescholl, Wageningen 69, 2639.Google Scholar
Ross, D. B. & Care, A. D. (1962). The movement of 28Mg2+ across the cell wall of guinea-pig small intestine in vitro. Biochemistry Journal 82, 21 p.Google Scholar
Smith, R. H. & Horn, J. P. (1976). Absorption of magnesium, labelled with 28Mg from the stomach of the young steer. Nuclear Techniques in Animal Production and Health, pp. 253–60. Vienna, Austria: IAEA.Google Scholar
Storry, J. E. (1961). Studies on calcium and magnesium in the alimentary tract of sheep. 1. The distribution of calcium and magnesium in the contents taken from various parts of the alimentary tract. Journal of Agricultural Science, Cambridge 57, 97102.CrossRefGoogle Scholar
Strachan, N. H. & Rook, J. A. F. (1975). Site of magnesium absorption in sheep. Proceedings of Nutrition Society 34, 1112A.Google Scholar
Suttle, N. F. & Field, A. C. (1968). Effects of intakes of copper, molybdenum and sulphate on copper metabolism in sheep. 1. Clinical condition and distribution of copper in blood of the pregnant ewe. Journal of Comparative Pathology 78, 351–62.Google Scholar
Tomas, F. M. & Potter, B. J. (1976). The site of magnesium absorption from the ruminant stomach. British Journal of Nutrition 36, 3745.Google Scholar
Wilson, A. A. (1960). Magnesium homeostasis and hypomagnesaemia in ruminants. Veterinary Reviews and Annotations 6, 3952.Google Scholar