Abstract: The effect of different sources of nitrogen supplementation on growth and reproductive performance of female goats and sheep under grazing condition. In addition to grazing, goats were allocated at random to three approximately iso-nitrogenous and iso-energetic supplemental diets. Average daily dry matter intake and live weight gain did not differ significantly both in goats and sheep received various sources of dietary N supplementation. The digestibility of all proximate components and nutritive value of supplemental diets was similar in goats and sheep. The results of the present studies showed that supplemental diets containing either soybean meal or till oil cake increased the growth rate of female goats and sheep. Therefore, feeding of goats and sheep with supplemental diet may be suggested under grazing condition.