Abstract: The family rangelands distributed in two grassland types of typical steppe and dessert steppe in Siziwang Banner of Inner Mongolia were used as research objects in this study. By field investigation of herdsmen, establishment of simulation analysis modeling and consultation of literatures, the parameters of grassland, livestock, feed, meteorology and economy were thoroughly assessed, and the grassland growth rate, energy balance status between forage and livestock as well as economic benefit were simulated, in hoping to provide reliable basis for guiding the sustainable management of local family rangelands. The results showed that the forage growth cycle in Siziwang Banner was relatively short. In summer, the forage growth rate in typical steppe area was higher than that in desert steppe area. The forage in the two types of grassland had poor cold-resistant capability, the growth of the most forage was hardly observed, and the above-ground parts of the forage were basically dead during winter time. Accordingly, for the raised livestock, energy obtained from the fresh forage was mainly concentrated in summer and autumn which were the forage growing seasons. Small- and medium-sized family rangelands were the main body of grassland overload. The smaller the grassland management area, the higher the stocking rate. There was also a positive correlation between forage expenditure and stocking rate. Both typical steppe area and desert steppe area showed that the short-term energy supply of grassland in summer was greater than the energy demand of livestock, and met the good growth condition of livestock. The winter was cold and long, and the energy intake of the livestock was low. The energy shortage during the lambing period in January was as high as 10.5 MJ/SE·d in typical steppe area, and that was as high as 9.5 MJ/SE·d in desert steppe area in the same duration. In conclusion, appropriately adjusting the stocking rate is conducive to the improvement of grassland comprehensive production capacity and the economic income of family rangelands in Siziwang Banner.

Key words: family rangelands, energy balance between forage and livestock, stocking rate, grazing