Calf-Manna® The Ideal Performance Supplement for Horses Calf-Manna will enhance the nutritional value of any feed, ensuring that your horse receives more performance from their feed. A unique aroma and palatability attract foals and keeps them coming back for more, and the great taste ensures that a stressed horse stays interested in feeding at a time when it’s crucial to do so. It also adds a sheen and luster to your horse’s coat to make for healthy, beautiful-looking animals.