The sprays need a pressure of 150-400 pounds per square inch. Use a quart to a gallon of spray on each animal. Some of those who must still practice patience are owners of pregnant broodmares. The answer is yes. For sometime horse owners have used artificial light to trick non-pregnant mares into earlier estrous each spring.
Mares are long-day breeders.
They used 16 hours of daylight and eight hours of darkness on a group of pregnant broodmares from Dec. 1 until they foaled in the spr ing. The use of extra light shortened the length of gestation by 10 days. The birth weight, height, heart girth as well as length and circumference of the cannon bone of these early foals were no different from those born later. Reproductive factors, such as time from foaling to ovulation, start of estrus and subsequent conception rates, weren't affected by the use of artificial light either. Thin broodmares carried their foals nine days longer than broodmares in moderate body condition.