Feline Formula Advanced Nutrition Supplement for Cats Give Them What They Want! Barley Grass Nutrition Barley Cat provides essential trace minerals, vitamins, proteins, amino acids, and chlorophyll Regular use promotes healthy skin and coat, freshens breath, supports digestion and restores energy levels especially among senior cats. Give your cat maximum health with great tasting super green nutrition. Barley Cat is the original "green" supplement made from Barley grass juice (grown without pesticides or chemical fertilizers) with a taste cats love.