Abstract: The study was conducted for Nine Fogera cows with average age, parity, initial body weight and stage of lactation was 9.3 year, 4.4, 262.7kg and 53.1 days, respectively used for the feeding trial were randomly assigned to three treatments. The treatments were 67% wheat bran and 33% NSC from 2kg concentrate + untreated rice straw (T1), 67% wheat bran and 33% NSC from 2kg concentrate +urea treated rice straw (T2) and 67% wheat bran and 33% NSC from 2kg concentrate + rice straw treated by effective micro-organism (T3). Animals were blocked based on their initial body weight in randomized complete block design. Feeding of Fogera cows with EMO treated rice straw resulted in significantly (p<0.05) higher daily dry matter intake (8.52 kg/cow, higher daily weight gain (27.7 g/day), higher daily milk yield (2.82l/day) and highest net income and marginal return rate (MRR) (82.6 and 194%, respectively) when compared with those cows fed on untreated rice straw. Hence, according to the results of this study feeding of lactating Fogera cows with EMO treated rice straw is efficient for both biologically and economically compared to urea treated rice straw.