Ostrich birds are browsers. They do not graze. They need food enrich with high nutrient value and high levels of vitamins and minerals. This types of food helps them to optimize their health and maximize their production.
The common food of ostrich are fruits, plants, roots, lizards, insects and various types of small rodents. They even consume sand, clams and small rocks for consuming the food properly.
For raising on a farm you can feed them the food of other poultry birds with vegetables and plants. Before providing supplementary food to ostrich make sure that all nutritious ingredients are available in their food.