The use of non-conventional feed resources (NCFR) either as replacement or as a supplement in the nutrition of livestock is discussed in this paper. The shortage of feed resources for livestock and poultry feeding diverted majority of research in the field of animal nutrition to look into possibilities to overcome this nutritional crisis. A possible and perhaps the most viable proposition could be the inclusion of non-conventional feed resources in livestock rations with suitable and complete feed technology that can utilize the feed sources with maximum efficiency. For the purpose of this review, potentially available NCFR include agro-industrial by products, some common tropical browse plants and leaf meals. It is known that some of these products are low in energy, proteins and contain high concentrations of lignin, silica and several anti- nutritional substances. Numerous multipurpose browse plants and leaf meals have been identified as having significant potential in agro-forestry systems in the tropics. Browse plants that have been identified and have recently been studied include Gmelina arborea, Myrianthus arboreus, Terminalia catappa, Dacroydes edulis, Parkia filicoidea and Tephrosia braceteolata. Protein from plant leaf sources is perhaps the most naturally abundant and cheapest source of protein, such that there has been growing realization in use of plant leaf meals in livestock diets. Several authors have conducted studies on these leaves to determine their nutritive values and usefulness in livestock nutrition. These include such plants as wildflower, Centroceama pubescens, cassava leaf meal, Microdermus puberula leaf meal, Vernonia amygdaliana leaf meal and Gliricidia sepium leaf meal. Results obtained from these studies have shown beneficial and economic values from the inclusion of these leaf meals in the diet of livestock.
