Journal Article

Short-term transport stress and supplementation alter immune function in aged horses

Barker, Virginia D., Harris, Patricia A., Adams, Amanda A., Miller, Ashton B.

2021

Overview

Long-distance transport is associated with stress-related changes in equine immune function, and shipping-associated illnesses are often reported. Horses are frequently transported short distances, yet the effects of short-term transport on immune function remain largely unknown. Twelve horses, aged 15–30 yr, were assigned to either the control (n = 6) or treatment (n = 6) groups; treatment horses received a daily antioxidant supplement 3 weeks before and after transport. All horses were transported for approximately 1.5–2 hr on Day 0. Blood was collected via jugular venipuncture at 15-min pre- and post-transport and on Days –21, 1, 3, 7, 14, and 21. Body temperature, heart rate, body weight, total cortisol, and gene expression of IFNγ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12α, IL-17α, SAA1, and TNFα in whole blood were measured. Peripheral blood mononuclear cells were isolated, stimulated with PMA/ionomycin, and stained for IFNγ and TNFα before analysis via flow cytometry. Statistical analyses were performed with significance set at P < 0.05 (SAS 9.4). Transport and supplementation did not appear to affect body weight, heart rate, IL-4, IL-8, IL-12α, IL-17α, change (Δ) in the % and mean fluorescence intensity (MFI) of IFNγ + lymphocytes after stimulation, or Δ in the % and MFI of TNFα + lymphocytes after stimulation. Supplementation decreased IL-1β and SAA1 expression. Transport increased total cortisol concentration, body temperature, and IL-2, IL-6, and IL-10 expression but decreased IL-1β, TNFα, and IFNγ expression. Short-term transportation affected physiological, endocrine, and immune responses; supplementation may ameliorate inflammation in aged horses. Immune responses were most altered at 15-min post-transport and typically recovered by Day 1, suggesting that horses may be vulnerable to disease during and almost immediately after short-term transport.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Age / Antioxidants / Biology and Life Sciences / Blood / Body temperature / Body weight / Environmental aspects / Flow cytometry / Fluorescence / Gene expression / Health aspects / Heart rate / Hormones / Horses / IL-1β / Immune response / Interleukin 10 / Interleukin 2 / Interleukin 4 / Interleukin 6 / Interleukin 8 / Ionomycin / Leukocytes (mononuclear) / Lymphocytes / Medicine and Health Sciences / Peripheral blood mononuclear cells / Statistical analysis / Stimulation / Supplementation / Supplements / Tumor necrosis factor-α / γ-Interferon