Energy and protein sources are of prime importance for ruminants as they stimulate microorganisms in the rumen and enhance the productive functions of the animals. Cassava roots in the form of dry cassava chips or pellets as energy sources and dried cassava leaves and cassava hay as protein sources have been used successfully in ruminant rations. These uses of cassava could provide year-round feed which results in a high yield and good quality of milk and contribute to a more lucrative dairy and beef cattle enterprise, especially for small-holder dairy farming systems. There are many other available feed resources in the tropics of potential use in ruminant feeding and particularly in the development of food-feed-systems that are not only beneficial for human and animals but also for the environment.