Genetic parameters and estimated breeding values of insect bite hypersensitivity in Belgian Warmblood horses.
Authors: Peeters Liesbet M, Janssens Steven, Brebels Machteld, Buys Nadine
Journal: Veterinary journal (London, England : 1997)
Summary
# Insect Bite Hypersensitivity in Belgian Warmbloods: A Heritable Concern Insect bite hypersensitivity (IBH) causes significant welfare and performance issues in horses, yet little has been known about its genetic basis in breeding populations. This study examined 3,409 Belgian Warmblood horses using questionnaire data collected at competitions, breeding events and through direct owner contact, classifying animals as affected or unaffected based on lifetime history and current clinical signs at assessment. The researchers found IBH prevalence of 10% when considering lifetime exposure to disease and 6.2% for active clinical cases, with heritability estimates ranging from 0.65–0.78 on the underlying biological scale (0.18–0.26 on the observed scale), indicating moderate to substantial genetic influence on susceptibility. These findings demonstrate that IBH is a genuinely heritable trait within this breed, suggesting that selective breeding strategies could meaningfully reduce prevalence over time. For breeding programmes, nutritionists, and veterinary clinicians, this work validates the importance of considering IBH status alongside traditional performance traits when making management and breeding decisions.
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Practical Takeaways
- •IBH is a genetically influenced condition affecting approximately 1 in 10 Belgian Warmblood horses at some point in their lifetime; breeders can use this information to make informed breeding decisions
- •Estimated breeding values (EBVs) for IBH susceptibility can be incorporated into selection criteria to reduce disease prevalence in breeding populations
- •The significant heritability suggests that breeding away from affected lines or known carriers could gradually reduce IBH incidence in the breed over generations
Key Findings
- •IBH prevalence in Belgian Warmblood horses was 10% based on lifetime history and 6.2% based on clinical signs at time of survey
- •Heritability of IBH susceptibility ranged from 0.65-0.78 on the underlying scale (0.18-0.26 on observed scale), indicating substantial genetic component
- •Susceptibility to IBH is a heritable trait in Belgian Warmblood horses, making it suitable for selective breeding programs