Assessment of oxidative stress parameters in summer anestrous buffaloes exhibiting differential fertility following melatonin implants treatment

For evaluating the impact of melatonin implants treatment during non-breeding season to ameliorate oxidative stress, 132 anestrous buffaloes were subcutaneously inserted with 2x4 mm absorbable slow-release melatonin implants (18 mg/50 kg b wt) at the base of left ear and 60 buffaloes were used as control. Ovarian ultrasonography and jugular vein blood sampling were carried out at 7-day interval till day 35 post-treatment or till ovulation, whichever was earlier. Control and implanted buffaloes were subjected to artificial insemination (AI) at overt or induced estrus followed by pregnancy diagnosis at day 90 post-AI. Erythrocytic lipid peroxidation (LPO) values were reduced (P<0.05) in implanted buffaloes from day 21 post-treatment onwards when compared to their pre-treatment and Control group values. However, the concentrations of erythrocytic glutathione peroxidase (GPx), glutathione reductase and superoxide dismutase (SOD) were invariably higher (P<0.05) following treatment as compared to their pre-treatment and Control group values. The buffaloes ovulating in Control or Treatment group revealed higher (P<0.05) erythrocytic GPx in the Latter group. Also, between pregnant counterparts of Control and Treatment group, the Latter group buffaloes exhibited low (P<0.05) erythrocytic LPO, and high (P<0.05) erythrocytic GPx, SOD and catalase. It can be concluded that melatonin implants treatment was successful for mitigating the oxidative stress in summer anestrous buffaloes, and the status of oxidative stress parameters following treatment was better in buffaloes that ovulated or conceived subsequently.