Blood plasma biochemical constituents play an important role in maintaining fertility hence experiment was carried out to study the biochemical parameters like blood urea nitrogen, creatinine kinase and cholinesterase in blood plasma of repeat breeding mehsana buffaloes following antibiotic treatment. Total eighteen health repeat breeder Mehsana buffaloes were selected and divided in three groups. Animals of Subgroups-I and II were treated with 4 gm Cephalexin powder and Ciprofloxacin 125 mg + Tinidazole 150 mg each dissolved in 60 ml of distilled water respectively, once only by intra uterine route, whereas in Group-II no treatment was advocated. Blood urea nitrogen levels showed noticeable significant changes which were comparatively higher in antibiotics treated Group-I as compared to untreated control (Group-II), whereas creatinine kinase and cholinesterase levels were not affected significantly which may be indicative of non infectious causative factors for repeat breeding condition. 1362323638.php