Thursday, December 23, 2010
Don't Forget to Leave The Lights On
I am not referring to those coming home for Christmas. It is your broodmare that I am concerned about. As you know, mares generally do not cycle through the winter months. Their ovarian cycle is influenced more by day length, then by ambient temperature. As the day length becomes longer in the spring, it triggers the mare to resume normal cycling. Since getting the mare cycling is the first step in getting her bred, now is the time to start "tricking" your mare into thinking the days are longer than they really are. The trick is to provided a total of 16 hours of light every day. If the mare is turned out during the day, then she needs to be stalled at night with the lights left on long enough to give her 16 total hours of light.
As a word of caution, it does not work well to just leave the lights on all the time. Some period of darkness is still necessary. Also, the light has to be fairly bright. The easiest way to assess if there is adequate light is to grab a newspaper and try to read the print in the darkest part of the stall. If you can not, then you either need a higher watt bulb or additional light sources.
It takes, on average, 70 days for a mare to have a breedable cycle after starting exposure to prolonged light. Mares will typically start to shed some of their hair with 30 to 60 days of starting lights. If you plan to breed your mare in February, she should already be on lights. If you do not care how early the foal is born, you do not have to mess with artificial lighting. Most mares will start cycling on their own by late March or early April.
As mares go from not cycling in the winter to having normal cycles in the spring, they go through a period of transition. During this period of transition they may have very irregular, non-fertile heats. If necessary, we can encourage them out of transiton more quickly with the use of certain medications.
If you intend to breed your mare early in 2011, make sure that right now she is seeing at least 16 hours of light every day.