The study was planned to see the effect of balance diet containing formaldehyde treated mustard oilseed cake (FT-MOC) on performance of lactating buffaloes. The 12 healthy early lactating Murrha buffalos of 3rd lactation were selected and they were randomly divided into 2 groups of 6 buffaloes each. The routine farmer’s practiced was considered as control (T1). In Treatment (T2) group feeding of roughage were similar as T1 and balanced concentrate mixture containing FT-MOC were fed as per nutrient requirement. Significant (P<0.05) difference in milk yield was observed. The fat, protein, lactose and total solid percentage of milk were recorded. The percent change in solid not fat (SNF) during experiment was noticed 0.32% in T1 and 0.96% in T2 groups of buffaloes. The experiment data indicated significantly higher values for haemato-biochemical parameters under study in buffaloes of treatment group than the control group. Balance diet containing formaldehyde treated (@ 1.2% of CP) mustard oilseed cake had significantly improved performance of the buffaloes.