Abstract: This review study was prepared with the objective of to revise the available scientific information about agro-ecological factors which are affecting the nutritional and biomass yield of forage species. There are several factors which are hindering livestock production on the world. Among them feed relating problem are the main constraints of livestock production. Therefore, to avail the feed relating problem knowing of the major factors which are affecting the animal feed quality and quantity have paramount importance. Among several factors which are influencing nutritive value and yield, agro-ecologies in which the forage species produced have vital role. Growing conditions (such as soil type, fertility, local climate, moisture conditions and pest pressure), stage of maturity at harvest, weather conditions during cutting, moisture at raking and baling and storage conditions are some of the factors which are influencing the growing condition and nutritive value of plant species. The nutritive value of a forage is the consequence of the conditions of plant growth. Understanding how environmental conditions and management factors interact to influence forage quality is important in making production decisions. The most obvious direct effect is leaching of nutrients from plants by rain. Many environmental conditions affect the chemical composition of plants indirectly, often by causing changes in the form or in the phenological development of plants.