PreprintArticleVersion 1Preserved in Portico This version is not peer-reviewed
Temporal Dynamics of Plasma Catecholamines, Metabolic and Immune Markers, and Corticosterone: DHEA Ratio in Farmed Crocodiles Before and After an Acute Stressor
Version 1
: Received: 13 June 2024 / Approved: 13 June 2024 / Online: 14 June 2024 (03:15:51 CEST)
How to cite:
Swanepoel, A.; Truter, C.; Viljoen, F.; Myburgh, J.; Harvey, B. Temporal Dynamics of Plasma Catecholamines, Metabolic and Immune Markers, and Corticosterone: DHEA Ratio in Farmed Crocodiles Before and After an Acute Stressor. Preprints2024, 2024060944. https://doi.org/10.20944/preprints202406.0944.v1
Swanepoel, A.; Truter, C.; Viljoen, F.; Myburgh, J.; Harvey, B. Temporal Dynamics of Plasma Catecholamines, Metabolic and Immune Markers, and Corticosterone: DHEA Ratio in Farmed Crocodiles Before and After an Acute Stressor. Preprints 2024, 2024060944. https://doi.org/10.20944/preprints202406.0944.v1
Swanepoel, A.; Truter, C.; Viljoen, F.; Myburgh, J.; Harvey, B. Temporal Dynamics of Plasma Catecholamines, Metabolic and Immune Markers, and Corticosterone: DHEA Ratio in Farmed Crocodiles Before and After an Acute Stressor. Preprints2024, 2024060944. https://doi.org/10.20944/preprints202406.0944.v1
APA Style
Swanepoel, A., Truter, C., Viljoen, F., Myburgh, J., & Harvey, B. (2024). Temporal Dynamics of Plasma Catecholamines, Metabolic and Immune Markers, and Corticosterone: DHEA Ratio in Farmed Crocodiles Before and After an Acute Stressor. Preprints. https://doi.org/10.20944/preprints202406.0944.v1
Chicago/Turabian Style
Swanepoel, A., Jan Myburgh and Brian Harvey. 2024 "Temporal Dynamics of Plasma Catecholamines, Metabolic and Immune Markers, and Corticosterone: DHEA Ratio in Farmed Crocodiles Before and After an Acute Stressor" Preprints. https://doi.org/10.20944/preprints202406.0944.v1
Abstract
Commercial crocodilian farms face significant economic and livestock losses attributed to stress, which may be linked to their adopted husbandry practices. The development of appropriate and modernized husbandry guidelines, particularly those focused on stress mitigation, is impeded by the limited understanding of the crocodilian stress response. Fifteen grower Nile crocodiles were subjected to simulated acute transport stress, with blood samples collected at various intervals post-stress. Plasma levels of corticosterone, dehydroepiandrosterone (DHEA), adrenaline, and noradrenaline were determined using high-performance liquid chromatography. Glucose and lactate were measured using portable meters, and the heterophil-to-lymphocyte ratio (HLR) was determined via differential leucocyte counts. Significant differences were elicited after the stressor, with acute fluctuations observed in the fast-acting catecholamines (adrenaline and noradrenaline) when compared to baseline. Downstream effects of these catecholamines and corticosterone appear to be associated with a persistent increase in plasma glucose and HLR. Lactate also showed acute fluctuations over time but returned to baseline by the final measurement. DHEA, used as a ratio with corticosterone, showed fluctuations over time with an inverted release pattern to the catecholamines. The study highlights the temporal dynamics of physiological markers under acute stress, contributing to understanding crocodilian stress and potentially informing improved farming practices for conservation and sustainable management.
Keywords
farmed crocodiles; stress response; monoamines; heterophil-to-lymphocyte ratio (HLR); corticosterone-to-dehydroepiandrosterone (CORT:DHEA) ratio
Subject
Biology and Life Sciences, Animal Science, Veterinary Science and Zoology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
