Determination of 13C/12C-Ratios in Rumen Produced Methane and CO2 of Cows,Sheep and Camels |
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Authors: | E Schulze S Lohmeyer W Giese |
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Institution: | Fachgebiet Medizinische Physik der Tier?rztlichen Hochschule , Hannover , Deutschland |
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Abstract: | Abstract Naturally produced methane shows different δ13C-values with respect to its origin, e.g., geological or biological. Methane-production of ruminants is considered to be the dominant source from the animal kingdom. Isotopic values of rumen methane—given in literature—range between ?80‰ and -50‰ and are related to feed composition and also sampling techniques. Keeping cows, camels and sheep under identical feed conditions and sampling rumen gases via implanted fistulae we compared δPDB 13C-values of methane and CO2 between the species. Referring to mean values obtained from 4 or 5 samples at different times of 11 animals (n = 47) we calculated δPDB 13C-medians resulting in small but not significant differences within and significant differences between the species for CO2 and methane. The δPDB 13C-differences between methane and CO2 were statistically equal within and also between the species. Therefore a linear regression of methane values on CO2 is appropriate and leads to: δPDB 13C(methane)‰ = 1,57 * δPDB 13C(CO2)‰-47‰ with a correlation coefficient of r = 0,87. |
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Keywords: | Camel carbon 13 carbon dioxide climatic factors cow intensive animal husbandry isotope effects methane ruminants sheep |
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