Abstract: Livestock slurries contain amounts of nitrogen, phosphorus and potassium which can be recycled in grass and arable system to reduce inorganic fertilizer inputs, but excess application of them can causepollution problems. Therefore, estimation of nutrients in slurries is required. A nalytical results of this paper show that different sets of predictive equations are required to different type of animal slurries, electrical conductivity (EC) and drymatter content (DM) are main factors for estimating slurry nutrient contents, and the multiple linear regression equations of EC and DM against nutrient contents have the potential to providemo rereliable and accurate indication of nutrient contents in animal slurries.