Abstract
ABOUT 99% of all carbon is the 12C isotope while 1% is 13C. The precise ratio of the isotopes will vary depending on the material analysed. In plants, fractionation of carbon is brought about primarily by carbon dioxide assimilation in photosynthesis and is due to preferential utilisation of 12C and exclusion of 13C. Curiously enough, it has been found recently1,2 that higher plants which fix carbon dioxide by way of the Calvin C3 cycle pathway differ in 13C/12C ratios from plants which fix carbon dioxide through the C4-dicarboxylic acid pathway. Temperate pasture species fix carbon by way of the Calvin pathway and have 13C/12C ratios of approximately −28‰ (ref. 3 and M.M.L., J.H.T., and R. J. Jones, unpublished), whereas tropical pasture grasses fix carbon through the C4-dicarboxylic acid pathway4 and have 13C/12C ratios of approximately −12‰ (ref. 2 and M.M.L., J.H.T., and R.J.J., unpublished). 13C/12C ratios are expressed relative to a carbonate standard5.
Similar content being viewed by others
Article PDF
References
Bender, M. M., Radiocarbon, 10, 468–72 (1968).
Tregunna, E. B., Smith, B. N., Berry, J. A., and Downton, W. J. S., Can. J. Bot., 48, 1209–1214 (1970).
Smith, B. N., and Brown, W. V., Am. J. Bot., 60, 505–513 (1973).
Ludlow, M. M., and Wilson, G. L., Aust. J. biol. Sci., 24, 449–470 (1971).
Smith, B. N., and Epstein, S., Pl. Physiol., Lancaster, 46, 738–742 (1970).
Troughton, J. H., in Photosynthesis and Photorespiration (edit. by Hatch, M. D., Osmond, C. B., and Slatyer, R. O.), 124–129 (Wiley Interscience, New York, 1971).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
MINSON, D., LUDLOW, M. & TROUGHTON, J. Differences in natural carbon isotope ratios of milk and hair from cattle grazing tropical and temperate pastures. Nature 256, 602 (1975). https://doi.org/10.1038/256602a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/256602a0
This article is cited by
-
Estimating the heritability of nitrogen and carbon isotopes in the tail hair of beef cattle
Genetics Selection Evolution (2024)
-
Revealing lost secrets about Yingpan Man and the Silk Road
Scientific Reports (2022)
-
Prey contribution to the diet of Octopus insularis (Leite and Haimovici, 2008) using stable isotopes and stomach content analysis in the Western Gulf of Mexico
Aquatic Ecology (2021)
-
Dietary histories of herbivorous loricariid catfishes: evidence from δ13C values of otoliths
Environmental Biology of Fishes (2006)
-
C and N stable isotope variation in urine and milk of cattle depending on the diet
Analytical and Bioanalytical Chemistry (2006)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.