Why do we want foal born
early in the year?


When a mare is in anestrus she is not cycling.  She doesn't produce a follicle (an egg) and cannot get in foal.  The mare is quite smart to have this behavior because anestrus occurs in the winter months when the weather is colder and food is more scarce.  A mare comes out of anestrus in the spring when the days become longer.  Surprise, surprise, the grass is growing, the sun is shining, the snow has melted and conditions are ripe to have a cute little foal so the mare's estrus cycle begins again, usually in April in New York.

The problem is man.  We being not overly smart, have decided that a horse's birthday is going to be January 1st.  Hence a horse born January 3, 1999 is considered a yearling on January 1, 2000.  A foal born October 23, 1999 is considered a yearling January 1, 2000.  Even though these horses are 10 months apart in actual age, they are both the same age on January 1, at least as far as any show animals are concerned.  
Now, if we are going to show a horse in the show ring, we have a much greater chance of impressing the judge if we have a nice big animal compared to a smaller horse.  In order for us to get a bigger horse, we have to have it born earlier.  Instead of switching the horses birthday to April 1st when nature intended the foals to be born, we in the showing community keep the birthday at January 1 and then try to do everything we can to have the mare have a baby as close to January first as possible, in order to utilize every competitive advantage possible. 
The problem is a mare doesn't want to have a baby in January when it is 10 below and the snow is howling about. (Hmmmm.... I don't think I would necessarily want to have a baby in that weather either.)  Refusing to cooperate with the mare, we turn to science to help us with our mare's anestrus problem.  The reason a mare goes into anestrus is based on the amount of light (or lack of it) that she receives. If you want to know if it is the amount of light or the amount of darkness that a causes anestrus, click here.

Bottom line on why we want foals born against what nature prefers... the show ring!