NAF Oestress Liquid. Find the angel in your moody mare with NAF Oestress Liquid. Offering a fast acting liquid which helps to compliment the mares natural oestrus cycle, Oestress Liquid helps to encourage regularity and hormone balance with the use of extracts of herbal ingredients with hundreds of years of use. Oestress offers bio-available magnesium to encourage muscle relaxation and calmness whilst the natural anti-oxidants help to support a healthy system. Oestress should be fed daily throughout the spring and summer months and may be increased during her oestrus cycle however Oestress can be used all year round if needed.