Turning out thoroughbreds

Question
What is the ideal(min/max)amount of time to turn out a race horse for the winter and how long would the horse need to train before it could make it back to the races? Most of the horses are 4-5 years old and were sound when they went to the farm.

Answer
IT IS DIFFERENT WITH EACH HORSE. ANYWHERE FROM 30 TO 90 DAYS

ONCE AGAIN EACH HORSE IS DIFFERENT WHEN IT COMES TO BRINGING THEM BACK TO THE RACES. A RULE OF THUMB WOULD BE THE SAME AMOUNT OF TIME AS THEY HAD OFF. HORSES THAT SPRINT WILL GET READY A LOT FASTER THAN HORSES THAT WANT TO RUN LONG.