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Seasonal dynamics in the vegetation and rumen microbial nitrogen (MBN) production and nutritional status of grazing sheep were investigated in a semiarid rangeland in eastern Rajasthan, India, to obtain some information for conserving the grazing land. Total number of plant species was 47, 71 and 47 in the summer, monsoon and winter seasons, respectively. The frequency of plant occurrence, density of plants and aboveground biomass were ranked monsoon > winter > summer, showing considerably low values in the summer season (10 - 32% of the monsoon values). Nutrient intake by animals was highest in the winter, followed by the monsoon and summer, with considerable summer depressions (32 - 64% of the winter values). Rumen MBN production per kg organic matter (OM) digested in the rumen was higher in the monsoon than in the summer and winter (66 and 60% of the monsoon value, respectively). Compared with the maintenance requirement, the animals were able to ingest only 58% of dry matter in the summer, 89% of digestible crude protein in the monsoon and winter, and 82 and 62% of metabolizable energy in the summer and monsoon, respectively. The removal of nutrients by animals via herbivory always exceeded the deposition via excreta, leading to the annual nutrient deficits of 187 kg OM, 1.7 kg N and 8.2 kg inorganic ash per sheep. The results highlight the need for developing means of nutrient replenishment to sustain the grazing resource, while accurate evaluation of the nutrient balance is warranted taking account of other pathways of inputs and outputs as well.