Development of Foals Until One Year of Age When the Dam was Exposed to Blue Monochromatic Light Directed at One Eye During Late Pregnancy.
Authors: Lutzer Anne, Nagel Christina, Aurich Jörg, Murphy Barbara A, Aurich Christine
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Blue monochromatic light exposure during late pregnancy has previously been shown to alter foal birth characteristics, prompting investigation into whether these changes persist beyond the neonatal period. Researchers monitored 40 foals (20 born to mares treated with blue LED light directed at one eye; 20 controls) for 12 months, measuring growth parameters, coat characteristics, and cardiac function, alongside haematological variables during the first month of life. Foals from treated mares exhibited shorter guard hair coats at birth, but this difference resolved by 2 months of age. Wither height and elbow-to-carpus distance remained slightly reduced in treated foals at birth and day 6, though these differences attenuated substantially with time. Haematological parameters (haematocrit, leukocyte and lymphocyte counts) changed appropriately with maturation in both groups without significant differences between them, whilst heart rate and heart rate variability developed normally, indicating physiological maturity and cardiovascular health. From a clinical and management perspective, these findings suggest that prenatal blue light exposure produces only transient morphological effects with no evidence of compromised health, growth trajectory or systemic function—implications worth noting for breeders considering experimental light protocols during gestation.
Read the full abstract on PubMed
Practical Takeaways
- •Blue LED light exposure of pregnant mares during late pregnancy does not compromise foal health or long-term growth; initial size differences at birth resolve within months
- •Foals born to treated mares demonstrate normal cardiovascular maturation and blood parameters, supporting safe use of this technology without welfare concerns
- •Early physical differences (height, hair length) are temporary and equalize by 2-6 months, suggesting the intervention has no lasting developmental impact
Key Findings
- •Foals born to blue LED light-treated mares had shorter guard hair at birth (P < 0.001) but no differences beyond 2 months of age
- •Wither height and elbow-to-carpus distance were reduced at birth in treated group (P < 0.01 and P < 0.05) but differences decreased over time
- •Heart rate, heart rate variability, and haematology parameters showed no significant differences between groups, indicating treated foals were mature and healthy
- •Blue LED light treatment of pregnant mares produced no detrimental effects on postnatal foal growth and development over one year