Equine Products Ireland Calm Equine. Calmer for horses and ponies. Used by top equestrians. Calm Equine is a complementary feed for horses and ponies containing supplementary levels of Vitamin B 1, Magnesium, Selenium and L-Tryptophan, which have important roles in stabilizing mood and in relieving panic and anxiety. Composition Magnesium Oxide, Maerl, Marine Magnesium Oxide, Dextrose.