Seminal plasma and serum fertility biomarkers in dromedary camels (Camelus dromedarius)

Eight healthy fertile (control) and 11 infertile male dromedaries were used to investigate whether specific seminal plasma and serum fertility biomarkers could be related to their in vivo fertility. Eight fertility biomarkers and testosterone were determined in both seminal plasma and serum of all studied camels during the rutting season using commercial kits. Results revealed a significant (P < 0.01) difference in semen parameters between the control and infertile camels. There was a significant (P < 0.01) difference between the control and infertile dromedaries in seminal plasma glutathione peroxidase (GPx) activity (15.04 ± 1.14 vs. 4.55 ± 0.96 nmol/min/mL, respectively) and both phospholipase A2 (sPLA2; 50.66 ± 6.28 vs. 23.56 ± 4.29 pg/mL, respectively) and testosterone concentrations (732.14 ± 57.12 vs. 396.36 ± 79.34 pg/mL, respectively). A significant (P < 0.05) difference was found between the control and infertile camels in seminal plasma concentrations of osteopontin, cysteine-rich secretory protein 3 (CRISP3), and prostaglandin D synthase (lipocalcin-type). There was a significant (P < 0.01) difference between the fertile and infertile camels in serum GPx activity 67.81 ± 12.41 vs. 21.31 ± 4.63 nmol/min/mL, respectively) and both testosterone (599.57 ± 110.90 vs. 176.09 ± 24.05 pg/mL, respectively) and clusterin concentrations (137.29 ± 14.15 vs. 253.00 ± 17.14 ng/mL, respectively). A significant (P < 0.05) difference existed between the control and infertile male dromedaries in serum concentrations of sPLA2, CRISP3, malonialdehyde, and insulinlike growth factor 1. In conclusion, CRISP3, sPLA2, GPx, and testosterone are fertility-associated biomarkers in both seminal plasma and serum of dromedary camels. Seminal plasma osteopontin is positively correlated and prostaglandin D synthase (lipocalcin-type) is negatively correlated with camels' fertility. Serum malonialdehyde, insulinlike growth factor 1, and clusterin are negatively correlated with fertility of male dromedary camels.