The foaling season was specifically designed to ensure maximum survival of the offspring. Therefore, in the wild the foaling season is in the spring and early summer, so the winter weather was over before the newborn arrived and yet there was time for the foal to grow and become self-sufficient before winter hit again. The mechanism for this seasonal control is increasing daylight. Sunlight or light from most light bulbs has the correct intensity and wavelength to stimulate a photoactive chemical (Rhodopsin), which is located in the eye (retinal rods). This in turn regulates the pineal gland (located deep in the brain) which in turn starts the mare into her cyclic rhythm.

In normal conditions (natural sunlight) the average time to first ovulation (releasing of an egg) is April. If we want to move up this time frame we can do so by the use of artificial lights. Starting eight to ten weeks before the desired breeding time (beginning of December for February 15 breeding) add artificial light for a total of 16 hours of daylight. It is important to have a dark period also, so don’t leave the lights on all the time (16 hours of light and 8 hours of darkness).

A 200 watt bulb located over an average stall within 4 yards of the mare will do. Extending the daylight seems to work best so as the sun goes down have a timer to keep the light on until 11:00 p.m. then automatically shut off to achieve the dark period. It is not necessary to start shorter and increase the time (although this works too).

By this artificial control we are able to achieve earlier foals for showing and racing, etc. However, remember the early born foal in this northern climate will have to have a dry and possibly heated stall to survive our usual January through March weather. Also, remember the mare will shed her winter hair earlier while under lights and you will have to make appropriate shelter and blankets available.