Mare's milk is not a significant source of nutrients for the foal after about four months, though it does no harm to a healthy mare for a foal to nurse longer and may be of some psychological benefit to the foal. A mare that is both nursing and pregnant will have increased nutritional demands made upon her in the last months of pregnancy, and therefore most domesticated foals are weaned sometime in the autumn in the Northern Hemisphere if the mare is to be bred again the next season.