Doves are strict vegetarians and exclusively seed eaters, with 99 percent of their diet seeds. They rarely feed on insects or other items, an unusual practice among birds, who usually eat high-protein foods such as insects, at least while they are young. 
Doves prefer a wide range of seeds. They find food by sight or by seeing other birds feeding and they remember where they have found choice foods. Favorite foods are determined by taste, and the size of the seed is not an important factor. Choice foods include many species of wild and cultivated grasses as well as weeds, including euphorbias, crotons, ragweed, amaranth and many others.
Legumes are almost never choice dove foods although doves do eat peanuts, peas. beans and some other legumes. Doves do not tend to eat acorns, or seeds of clovers, chufas, partridge peas, vetches and other plants.
Doves love millet sprays, both small and the larger type. Keep a spray of millet clipped to the side of the cage where the Doves can nibble on them.
The most important part of the Doves' meal is to have continuous access to fresh water each day. The water should be at least an inch or more deep since the Doves drink with their bill straight down like sucking through a straw. The water dish should be clean from slime and debris.