Amino acid δ ¹⁵N values are associated with underweight status in a captive population of muskoxen.
- 1Institute of Arctic Biology, University of Alaska Fairbanks, 2140 Koyukuk Drive, Fairbanks, Alaska 99775-7000, USA.
- 2Department of Biology and Wildlife, University of Alaska Fairbanks, 2090 Koyukuk Drive, Fairbanks, Alaska 99775-6100 USA.
- 3Animal Resources Center, University of Alaska Fairbanks, 1033 Sheenjack Drive1033 Sheenjack Drive, Fairbanks, Alaska 99775-6980, USA.
Abstract
Measures of protein balance, particularly changes in body mass, are important in understanding the health of wildlife populations but can be difficult or impossible to obtain from free-living animals. One potential biomarker, the δ¹⁵N value of bulk tissue, has had mixed associations with body mass. δ¹⁵N values of amino acids (AAs) have been shown to be more sensitive measures of trophic position than the bulk δ¹⁵N value and may also be more sensitive to changes in body mass. Here we evaluate AA δ¹⁵N values as a method to assess underweight status using archived serum samples from a captive population of muskoxen (Ovibos moschatus) that had decreased body mass resulting from an inadvertent dietary trace element deficiency. We predicted that AA δ¹⁵N values would be associated with deviations from the expected healthy body mass based on sex and age, and that they would be more sensitive than bulk δ¹⁵N values. We evaluated several linear mixed-effect models with δ¹⁵N values of bulk serum, AAs and other variables against deviations from expected body mass. In females, the δ¹⁵N values of glutamate/glutamine, leucine, aspartate/asparagine and serine, plus pregnancy status, were best associated with the difference from expected mass; in males, the δ¹⁵N values of glutamate/glutamine, leucine and proline were best associated with the difference from expected mass. Bulk δ¹⁵N values were not associated with the difference from expected mass. δ¹⁵N values of AAs have potential as a tool for researchers to evaluate body condition in animals.
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BibTeX
@article{savory2026amino,
title = {{Amino acid δ ¹⁵N values are associated with underweight status in a captive population of muskoxen.}},
author = {Garrett A Savory and Molly Cook and Greg A Breed and John Blake and Diane M O'Brien},
journal = {Conservation physiology},
year = {2026},
month = oct,
doi = {10.1093/conphys/coag080},
url = {https://europepmc.org/article/MED/42923832},
note = {CC BY},
}
RIS
TY - JOUR
TI - Amino acid δ ¹⁵N values are associated with underweight status in a captive population of muskoxen.
AU - Garrett A Savory
AU - Molly Cook
AU - Greg A Breed
AU - John Blake
AU - Diane M O'Brien
PY - 2026
DA - 2026/10/22
JO - Conservation physiology
DO - 10.1093/conphys/coag080
UR - https://europepmc.org/article/MED/42923832
AB - Measures of protein balance, particularly changes in body mass, are important in understanding the health of wildlife populations but can be difficult or impossible to obtain from free-living animals. One potential biomarker, the δ¹⁵N value of bulk tissue, has had mixed associations with body mass. δ¹⁵N values of amino acids (AAs) have been shown to be more sensitive measures of trophic position than the bulk δ¹⁵N value and may also be more sensitive to changes in body mass. Here we evaluate AA δ¹⁵N values as a method to assess underweight status using archived serum samples from a captive population of muskoxen (Ovibos moschatus) that had decreased body mass resulting from an inadvertent dietary trace element deficiency. We predicted that AA δ¹⁵N values would be associated with deviations from the expected healthy body mass based on sex and age, and that they would be more sensitive than bulk δ¹⁵N values. We evaluated several linear mixed-effect models with δ¹⁵N values of bulk serum, AAs and other variables against deviations from expected body mass. In females, the δ¹⁵N values of glutamate/glutamine, leucine, aspartate/asparagine and serine, plus pregnancy status, were best associated with the difference from expected mass; in males, the δ¹⁵N values of glutamate/glutamine, leucine and proline were best associated with the difference from expected mass. Bulk δ¹⁵N values were not associated with the difference from expected mass. δ¹⁵N values of AAs have potential as a tool for researchers to evaluate body condition in animals.
SN - 2051-1434
ER -