By definition, range is the primary feed resource of this system. Quality varies widely. Oceania's systems involve top-dressing with fertilizers, introduction of legumes, appropriate fencing to achieve highly productive legume-grass pastures. Relatively even rainfall distribution and seasonal mating allow for comparatively high productivity levels using a minimum of hay or silage. In the less intensive grazing systems of Africa and Asia, seasonal fluctuations in feed supply are mainly buffered by the loss of weight of the animals. This, however, limits their productivity.