Effects of blue monochromatic light directed at one eye of pregnant horse mares on gestation, parturition and foal maturity.

This research investigates the effects of exposing pregnant mares to blue LED light on gestation time and characteristics of their foals. The study concludes that blue light exposure advances foaling and affects the height and hair production of the foals, without influencing their weight.

Methodology and Participants

• The research was conducted over two years on a total of 20 mares with solitary pregnancies arranged into a cross-over design.
• In one year of the study, these mares were subjected to a prolonged photoperiod of blue LED light at 50 lux (468 nm) directed at one eye daily from 08:00 to 23:00, beginning in mid-December. The mares wore light masks to achieve this.
• In the other year, the mares remained untreated and served as a control group.

Results

• The study found that the gestation period in blue light-treated mares was shorter than that in control pregnant mares (median 333.0 vs 338.5 days).
• Foals born to mares exposed to blue LED light had lower wither heights when compared to those of control foals (median 103.0 vs 104.5 cm).
• The birth weights of the foals from both groups were similar (median 55.8 vs 54.8 kg).
• Foals from blue light-treated mares took less time to stand after birth than those from the control group (median 35.0 vs 53.5 minutes).
• Foals from lit mares had reduced hair length compared to the controls (median 12.0 vs 20.0 mm) and experienced reduced hair regrowth.

Conclusion

• The study concludes that exposure to blue LED light directed at one eye hastens foaling in mares.
• This practice also impacts the height and hair coat of the foals, but it does not have any effect on their weight.