Abstract: The experiment was carried out to evaluate the effect of Effective Microbes (EM) treated grass hay on feed intake, digestibility, growth performance and economic feasibility of Washera sheep fed on natural grass hay basal diet. Twenty Four growing (8-9 month) intact male Washera sheep with initial body weight of 14.802±1.965kg (mean ± SD) were blocked in to six blocks based on initial body weight and animals within a block randomly assigned to treatment diets.