Relationship between plasma dopamine concentration and temperament in horses

Area of Science:

• Animal behavior science
• Neuroendocrinology
• Equine science

Background:

• Dopamine (DA) is a neurotransmitter influencing animal behaviors and temperament.
• The role of dopamine in horse temperament, particularly in relation to other neurotransmitters like oxytocin (OXT) and serotonin (5-HT), is not well understood.
• Understanding these neurochemical links can provide insights into equine behavior and welfare.

Purpose of the Study:

• To investigate the correlation between plasma dopamine concentrations and oxytocin and serotonin levels in horses.
• To determine the association between plasma dopamine concentration and specific horse temperament traits, including docility, fearfulness, dominance, and trainability.

Main Methods:

• Blood samples were collected from 31 horses.
• Plasma concentrations of dopamine (DA), oxytocin (OXT), and serotonin (5-HT) were quantified using enzyme-linked immunosorbent assay (ELISA).
• Horse temperament was assessed and scored by three independent researchers, with statistical analyses including linear regression, ANOVA, and t-tests.

Main Results:

• No significant correlation was found between plasma DA concentration and OXT or 5-HT concentrations.
• Plasma DA concentration showed no correlation with dominance or trainability in horses.
• A potential correlation was identified between plasma DA concentration and the degree of fearfulness in horses.

Conclusions:

• Plasma dopamine concentration is not associated with oxytocin or serotonin levels in horses.
• Dopamine levels do not appear to be linked to dominance or trainability.
• Plasma dopamine concentration shows potential as a biomarker for predicting the fearfulness of horses, offering insights into equine emotional states.