I agree. I usually put my mare under lights after the summer solstice to keep the day length consistent and breed in the first heat cycle of the year.
Originally Posted by iridehorses
For performance horses especially, you want a horse to deliver as close to the first week in January as possible. Since a horse turns a year older on January 1st, a foal born on January 6th will have a distinct advantage over a horse born on Decempber 23rd. Both being judged as a one year old on January 1st.
Since Futurities are for 3 year olds. The horse born on Jan 6 will be 11 months older then the one born on Dec 23rd.