What is the Flash Method of Lighting?

In order to bring the mare out of anestrus she must have at least 16 hours of light.  For most people this means setting up a timer to go on at 4:00 am and off at 8:00 PM.

However, it has been shown that if the normal melatonin production is interrupted by a pulse of light in the middle of the "dark" period of the day, you can fool the mare into thinking there are 16 hours of light.

The flash method of lighting uses a pulse of light in the middle of the dark period that interrupts the melatonin production.  The mare senses this as a shorter night.  If the nights are shorter then the days must certainly be longer.  If the lights are on for at least one hour between 1:00 a.m. - 4:00 a.m. you will produce the same effect as having the lights on for 16 hours.

I use 1-1/2 hours of light coming on at 1:30 a.m.

Note: If you have the lights on for more than 20 hours the effectiveness of bringing the mare out of anestrus is reduced! Leaving the lights on 24 hours a day is NOT as effective as 16 hours of daylight and/or the flash method of lighting.  It stands to reason, too, because the mare appears to measure the length of night.  If night never comes or doesn't come in a "long enough quantity" to have a consistent melatonin production cycle established then the mare can't determine if the days are getting longer or shorter.