Effect of exogenous progesterone treatment on ovarian steroid hormones and oxidant and antioxidant biomarkers during peak and low breeding seasons in dromedary she-camel

Background: Research about the effects of progesterone (P4) and the relationship of P4 to oxidative stress has been achieved in ruminants but not enough in camels Aim: This study evaluated the effect of exogenous P4 hormone using CIDR for 7 days on blood concentrations of steroid hormones and oxidative status of dromedary she-camels during peak and low breeding seasons. Materials and Methods: The present work was conducted on ten dark dromedary she-camels which were synchronized using a controlled internal drug release (CIDR) for 7 days as a reproductive management tool during peak breeding (November-April) and low breeding season (May-October). The blood samples were collected each other day from CIDR insertion until the end of experiment 5 days after the removal of CIDR. Camels were examined for P4, estradiol (E2), and testosterone (T) as well as malondialdehyde (MDA) as indicator of lipid peroxidation and nitric oxide, superoxide dismutase (SOD), and glutathione-S-transferase as antioxidant markers. Results: Results revealed that P4 was higher during peak breeding season than low breeding season. While the levels of P4 increased during CIDR insertion and declined at CIDR removal and thereafter during breeding season, its concentrations declined after CIDR application during the non-breeding season. On the other hand, blood E2 and testosterone levels decreased after CIDR insertion in both high and low breeding seasons with higher serum E2 concentrations during the peak than the low breeding season. MDA concentrations and SOD activities were significantly (p