Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jan;104(1):104494.
doi: 10.1016/j.psj.2024.104494. Epub 2024 Nov 2.

Transportation increases circulating corticosterone levels and decreases central serotonergic activity in a sex dependent manner in Pekin ducks

M M Bergman  1 , J M Schober  1 , R Novak  1 , A Grief  1 , C Plue  1 , G S Fraley  2
Affiliations

Transportation increases circulating corticosterone levels and decreases central serotonergic activity in a sex dependent manner in Pekin ducks

M M Bergman et al. Poult Sci. 2025 Jan.

Abstract

Previous studies from our lab suggest that transportation of early adulthood ducks can have long lasting physiological effects. To better understand how transportation affects the ducks' physiology, we evaluated several central and peripheral parameters. Thirty-six, 23-week-old ducks were collected at a commercial breeder facility and randomly assigned to one of three treatment groups (n = 6/sex/treatment): 1) caught and euthanized (control), 2) caught and put in a crated in the pen for 90 min (crate), or 3) caught, crated, and transported in a truck for 90 min (transport) to simulate actual transportation. Blood was collected for serum corticosterone and blood smear analyses. Brains were hemisected and each half was dissected into three brain areas: caudal mesencephalon (CM), rostral mesencephalon (RM), and diencephalon (DI). Mass spectrometry was run on the right half of the brain, and gene expression of TPH1, TPH2, TH, CRH, and NPY were measured on the left half of brain using qRT-PCR. Serum corticosterone levels were increased (p = 0.01) in crated hens and in transported hens and drakes (p = 0.0084) when compared to control. HLR was increased (p = 0.035) in crated hens and transported hens and drakes compared to control. No differences in serotonin turnover were observed in drakes but increased in hens within the CM and RM from control to crate (p = 0.01) and crate to transport (p = 0.016). There were no differences in DA turnover or in gene expression for all brain areas for drakes and CM and RM for hens. Within the DI, hens showed a decrease (p = 0.03) in TPH1 for transport compared to crate. Overall, transportation elicits an acutely stressful event that increases corticosterone and HLR in a sex dependent manner where hens appear to be more reactive to the stressor than drakes. Our data supports that when assessing a stress response, care must be given to the sex of the bird and to the relative timepoint of sampling compared to the perceived onset of the stressor.

Keywords: Brain; Neurotransmitter; Sex differences; Stress.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest The authors declare no conflict of interest.

Figures

Fig 1:
Fig. 1
(A) Serum corticosterone levels of Pekin duck hens and drakes. Ducks (n = 6/sex/treatment) were collected from their pen (CON), crated (CRA), and crated and transported (TRA). Serum corticosterone increased (p = 0.01) for CRA hens while CRA drakes remained similar to CON. For TRA drakes and hens, corticosterone was increased (p = 0.0084) compared to all other treatments. (B) Heterophil to lymphocyte ratio (HLR) for Pekin duck hens and drakes. Ducks (n = 6/sex/treatment) were collected from their pen (CON), crated (CRA), and crated and transported (TRA). Hens show an increase in HLR for CRA and TRA while drakes show an increase for TRA (p = 0.035).
Fig 2:
Fig. 2
Serotonin (5-HT) for Pekin duck brains. Three brain areas (CM, RM, DI) (n = 6/sex/treatment) were collected from their pen (CON), crated (CRA), and crated and transported (TRA). (A) Hens. The CM and RM brain areas show a significant increase in 5-HT turnover from CON to CRA (p = 0.01) and CRA to TRA (p = 0.016). No significant differences in DI. (B) Drakes. There were no significant differences across treatments. (C) Serotonin static levels (ng/mg) for hens. (D) Serotonin static levels (ng/mg) for drakes. There were no significant differences in static levels of serotonin. (E) 5HIAA static levels in the hen. (F) 5HIAA static levels in the drake. There were no significant differences in static levels of 5HIAA.
Fig 3:
Fig. 3
Dopamine (DA) for Pekin duck brains. Three brain areas (CM, RM, DI) (n = 6/sex/treatment) were collected from their pen (CON), crated (CRA), and crated and transported (TRA). (A) Hens. No significant differences in CM, RM, or DI. (B) Drakes. No significant differences in CM, RM, or DI. (C) Dopamine static levels (ng/mg) for hens. (D) Dopamine static levels (ng/mg) for drakes. There were no significant differences in static levels of dopamine.
Fig 4:
Fig. 4
qRT-PCR within the brain for drakes. Fold change compare target genes to housekeeping genes to measure relative mRNA expression of TPH1, TPH2, TH, CRH, and NPY. (A) The CM brain area showed no significant differences. (B) The RM brain area showed no significant differences. (C) The DI brain area showed no significant differences.
Fig 5:
Fig. 5
qRT-PCR within the brain for hens. Fold change compare target genes to housekeeping genes to measure relative mRNA expression of TPH1, TPH2, TH, CRH, and NPY. (A) The CM brain area showed no significant differences. (B) The RM brain areas showed no significant differences. (C) For TPH1, TRA hens show decrease (p = 0.030) in fold change when compared to CRA hens. All other target genes show no significant differences.
See this image and copyright information in PMC

References

    1. Alaqil A.A., Zulkifli I., Bejo M.H., Sazili A.Q., Rajion M.A., Somchit M.N. Changes in heat shock protein 70, blood parameters, and fear-related behavior in broiler chickens as affected by pleasant and unpleasant human contact. Poult. Sci. 2013 https://pubmed.ncbi.nlm.nih.gov/23243228 Available at. - PubMed
    1. Bahry M.A., Chowdhury V.S., Yang H., Tran P.V, Do P.H., Han G., Ito H., Ikeda H., Cockrem J.F., Furuse M. Central administration of neuropeptide Y differentially regulates monoamines and corticosterone in heat-exposed fed and fasted chicks. Neuropeptides. 2017 https://pubmed.ncbi.nlm.nih.gov/27979380 Available at. - PubMed
    1. Beaulac K., Crowe T.G., Schwean-Lardner K. Simulated transport of well- and poor-feathered brown-strain end-of-cycle hens and the impact on stress physiology, behavior, and meat quality. Poult. Sci. 2020 https://pubmed.ncbi.nlm.nih.gov/33248591 Available at. - PMC - PubMed
    1. Bergman M., Schober J., Oluwagbenga E., Frey D., Parnin H., Fraley G. Preening cups in duck housing are associated with an increase in central dopamine activity that suggests a negative affective state. Poult. Sci. 2024 https://pubmed.ncbi.nlm.nih.gov/38479100 Available at. - PMC - PubMed
    1. Boissy A., Manteuffel G., Jensen M.B., Moe R.O., Spruijt B.M., Keeling L.J., Winckler C., Forkman B., Dimitrov I., Langbein J., Bakken M., Veissier I., Aubert A. Assessment of positive emotions in animals to improve their welfare. Physiol. Behav. 2007 https://pubmed.ncbi.nlm.nih.gov/17428510 Available at. - PubMed