In tropical Indonesia, which has specific dry and wet seasons, it is difficult to provide high-quality forage in sufficient quantities throughout the year. Therefore, it is necessary to establish the availability and nutrient contents of forages and other natural feed resources during the dry and wet seasons in order to provide sufficient nutrients throughout the year, as an improvement effort the productivity of dairy cows. The method used was surveys conducted at dairy smallholder and groups selected in one of the areas of dairy cooperative in Yogyakarta; and observed environment condition (temperature and humidity). Feed samples were taken and analyzed in the Laboratory of Dairy Science and Milk Industry, Faculty of Animal Science UGM. Supplies of forages, agricultural by-products, feedstuffs, and commercial concentrates were available throughout the year, although the amounts were limited. Most of dairy smallholders had greater access to forages and agricultural by-products during wet season than during the dry season; this resulted directly in a better productivity of dairy cows during the wet season. In both seasons, farmers purchased commercial concentrates from other areas to support the cows feed requirements. Smallholder dairy farmers in the dairy areas of Yogyakarta had better access to forages and agricultural by-products during the wet season than during the dry season, but need to supplement their animals with commercial concentrates obtained from outside areas during both seasons. Assuring the continuity and availability of forages and concentrate in this area is of dire importance to reduce the dependency of feed from outside of the region.