The impact of barefoot racing in young Swedish trotters on career length.

Overview

• This study investigates how racing barefoot (without horseshoes) affects the career length of young Swedish trotters, specifically Swedish Standardbred and Swedish-Norwegian Coldblooded trotters.
• The research focuses on understanding whether the increased wear on hooves from barefoot racing leads to shorter racing careers, given concerns about hoof damage and animal welfare.

Background and Motivation

• Barefoot racing is a common practice in European trotting races aimed at improving speed.
• Some horses’ hooves can tolerate barefoot racing without excessive wear and damage, while others cannot.
• Particularly, durable hind hooves are important because these hooves bear much of the stress during racing.
• Previous studies indicate genetic differences affect the likelihood of horses racing barefoot, especially between the two breeds studied: Swedish Standardbred (SB) and Swedish-Norwegian Coldblooded trotters (CB).
• Since horseshoes protect the hooves against wear and tear, racing barefoot removes that protection and may cause welfare issues if hooves are damaged.
• There is ongoing debate and varying regulations across Europe regarding barefoot racing for young horses, but scientific studies on this topic have been lacking.

Study Objective

• The main aim was to examine if racing barefoot on the hind hooves at a young age influences the length of a horse’s racing career.
• This was studied by analyzing data on thousands of horses, looking at how much they raced barefoot and monitoring when their careers ended.

Data and Methods

• Data sets included shoeing information for:
  • 3-year-old Swedish Standardbred trotters (SB)
  • 3- and 4-year-old Swedish-Norwegian Coldblooded trotters (CB)
• Sample sizes were large, totaling up to 12,161 horses.
• Statistical analysis used Cox proportional hazard models to evaluate how the proportion of barefoot races at a young age affected the hazard (risk) of ending the horse’s career over time.
• Several factors were controlled for in the models, including:
  • Sex of the horse
  • Year of birth
  • Whether the horse started racing at 2 years old (for SB)
  • Early earnings
  • Best racing time
  • Number of early race starts

Key Findings

• Swedish Standardbred trotters (SB):
  • Horses racing more than 30% of their races barefoot had a 14% higher risk of ending their career at any given point compared to those racing barefoot 5% or less.
  • Median career length reduced by 123 days in males and 85 days in females who raced more than 50% barefoot.
  • The reduction in career length was considered minor overall, despite the increased hazard.
• Swedish-Norwegian Coldblooded trotters (CB):
  • The hazard of career termination was 67% higher for horses with the highest proportion of barefoot races compared to the reference group.
  • The negative effect on career length was more pronounced than in SB but based on fewer observations, suggesting caution in interpretation.

Interpretations and Implications

• The study provides evidence that racing barefoot as a young horse is associated with an increased risk of ending a racing career earlier.
• These outcomes could be related to hoof wear and damage due to lack of shoe protection, especially on the hind hooves.
• Despite the increased hazard, the impact on career length varies between breeds and is quantitatively modest in some cases (SB) but larger in others (CB).
• There are welfare concerns about barefoot racing, especially in young trotters whose hooves might not yet be durable enough.
• Regulatory bodies should consider these findings when setting rules about barefoot racing, especially concerning young horses.

Conclusions and Further Research

• This study fills a gap by providing scientific evidence on barefoot racing effects using a large dataset.
• It emphasizes the importance of considering hoof durability and the possible negative impact on horse welfare.
• Future research should delve deeper into the reasons horses end their careers—whether voluntarily or due to injury—to better understand the causes linked to barefoot racing.
• Such work could inform safer practices and regulations for young trotters in harness racing.