Effect of transport on the intensity of stress reactions in mares and foals.

The research article focuses on how transportation affects the behavioral and hormonal stress responses in mares and their foals, as indicated by plasma concentrations of adrenaline, noradrenaline and cortisol.

Objective and Methodology:

• The goal of the study was to understand the influence of transportation on stress levels in mares and their foals, specifically looking at the sympatho-adrenal and hypothalamo-pituitary-adrenal systems.
• To measure this, the researchers looked at peripheral plasma concentrations of adrenaline, noradrenaline, and cortisol, hormones that are released during periods of stress. Control blood samples were taken from both mares and their foals (a total of 5 pairs) on the eighth day after birth, to determine the baseline for these hormone levels.

Experimental Procedure:

• The actual experimentation occurred during foal oestrus, on day 9 after birth. The transportation process induced stress, which allowed the researchers to measure variations in the hormones in the mares’ and foals’ blood plasma.
• Concentration of adrenaline and noradrenaline in mares’ blood increased just after 10 minutes of transportation and maintained this higher level until 30 minutes after transportation ended.
• For foals, adrenaline and noradrenaline concentrations also increased after 10 minutes, but unlike the mares, these levels decreased rapidly to baseline levels.
• Cortisol, another stress hormone, reached peak levels in mares’ plasma after 60 minutes of transportation. Foals, on the other hand, reached their peak cortisol levels only after transportation had concluded.

Conclusion and Findings:

• The authors conclude that transportation during foal oestrus causes more significant stress for mares than for their foals, as evidenced by the longer maintenance of heightened adrenaline and noradrenaline levels and delayed peak cortisol levels in mares.
• This study provides significant insights about the effects of transportation stress in mares and their foals, and may inform better management and care strategies in equine husbandry.