The mane effect in the horse (Equus ferus caballus): Right mane dominance enhanced in mares but not associated with left and right manoeuvres in a reining competition.

This research investigates the predominance of horses’ mane direction and its relationship with their performance in reining competitions, finding that the mane direction is more likely to be to the right, especially in females, but it doesn’t influence the horses’ performance or maneuvering ability.

Exploring Mane Asymmetry in Horses

• The core of this research revolves around the study of hair-whorl asymmetry in horses, specifically, the mane’s direction. A sample consisting of 526, 3-year-old American Quarter horses was studied. Researchers noted that 69% of horses had their mane directed to the right, while 31% had their manes directed to the left.
• The team observed a more significant bias in the females, where 74% had their manes directed to the right compared to 65% in males, making this a more common trait in female horses.
• The research found no relation between the mane direction and the coat color of the horse.

Evaluating the Impact on Reining Competition Performance

• The trials attempted to determine if the mane direction affected the horses’ performance in a reining competition, which requires various symmetrical manoeuvres such as spinning, circling, and roll-back to either the left or right.
• However, no relationship was discovered between mane asymmetry and the overall reining performance. Furthermore, there was no correlation found between the mane’s direction and scores for left or right maneuvers.

Interpretation of the Results

• Results are interpreted in relation to the role of morphological asymmetries, neural function, and the genes controlling planar cell polarity, including Frizzled. These genes have an impact on epidermal hair cell patterning, which may contribute to the mane direction.
• Despite the observed asymmetry in mane direction, the research concluded that mane direction does not influence horse maneuvering abilities or performance in reining competitions.