Why would a herdsperson put a mare under 2 foot-candles of light for 14-16 hours per day?

Providing a mare with exposure to 2 foot-candles of light for 14-16 hours a day is a practice often employed to stimulate ovarian activity. Horses are seasonal breeders, particularly in temperate climates, with their natural reproductive cycles influenced by the length of daylight. When mares are exposed to prolonged periods of light, it mimics the longer days of spring, encouraging their bodies to enter the breeding season. This process effectively increases the production of hormones like estrogen, which is essential for ovarian activity and the overall reproductive cycle.

In addition, this light stimulation can help synchronize estrus cycles, making it beneficial for breeding management. Therefore, the correct answer highlights the importance of light exposure in enhancing the reproductive capabilities of mares, aligning their cycles with optimal breeding times. This practice is particularly useful in controlled breeding programs, where timing is crucial for successful outcomes.