The present study evaluated the serum profile changes in biochemical constituents in 18 postpartum anestrus (>60 days) cows, treated under field conditions with Estrona feeding at 125gm/day/animal for four days (group II; n=6) or CIDR-Synch protocol (group III; n=6) and untreated control (group I; n=6). The overall mean calcium and phosphorus concentration (mg/dL) varied significantly (P<0.05) within group II and mean glucose concentration varied significantly (P<0.05) in group III. However, no-significant difference was observed in cholesterol concentration observed in groups I, II, and III, before (0th day) and after (30th day) treatment. To conclude, the above results indicate that there was significant difference in serum calcium and phosphorus in Estrona feeding group before and after the treatment in postpartum anestrus cows.