title: Does natural weathering change the stable isotope composition (²H, ¹³C, ¹⁵N, ¹⁸O and ³⁴S) of cattle hair?
abstract: Stable isotope analysis of hair has found applications in many fields of science because it provides a temporally resolved, fairly stable isotopic archive of mammalian individuals. We investigated whether this hair archive is modified by natural weathering while attached to a living animal. We analyzed the tail switch hairs of one suckler cow, sampled seven times over a period of four annual summer pasture-winter stall feeding cycles. We compared relative isotope ratios (δ²H, δ¹³C, δ¹⁵N, δ¹⁸O and δ³⁴S) of sections of hair that grew simultaneously but were exposed to natural weathering conditions over different periods of time. Natural wear caused a loss of mass of approx. 0.13% day⁻¹, with no apparent effect of environmental conditions. Changes in δ²H, δ¹³C, δ¹⁵N and δ¹⁸O were below the detection limit, indicating that hair is a reliable archive for the isotopes of these elements. In contrast, δ³⁴S values increased during the grazing period by about 1‰, with exposure to UV radiation appearing to have a major influence on this result. The δ³⁴S values decreased during the subsequent stall period, probably due to abrasion. Seasonal variation in δ³⁴S may indicate alternating environments that differ in their weathering conditions.
authors.affiliation: Lehrstuhl für Grünlandlehre, Technische Universität München, Freising-Weihenstephan, Germany. auerswald@wzw.tum.de
authors.forename: Karl
authors.initials: K
authors.lastname: Auerswald
authors.forename: Andreas
authors.initials: A
authors.lastname: Rossmann
authors.forename: Rudi
authors.initials: R
authors.lastname: Schäufele
authors.forename: Michael
authors.initials: M
authors.lastname: Schwertl
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Monahan
authors.forename: Hans
authors.initials: H
authors.lastname: Schnyder
mesh_terms: D000818:Animals; D002417:Cattle; D006197:Hair / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D060434:Herbivory; D007554:Isotopes / Q000032:analysis*; D057230:Limit of Detection; D012044:Regression Analysis; D015203:Reproducibility of Results; D012621:Seasons; D012680:Sensitivity and Specificity; D013623:Tail; D014887:Weather
chemical_list: D007554:Isotopes