Supplemental dietary curcumin improves testicular hemodynamics, testosterone levels, and semen quality in Baladi bucks in the non-breeding season

Improving the reproductive performance outside the breeding season could have a great impact on the animals' breeding industry. Curcumin (CUR) is a polyphenol known for its multi-effects on different biological issues due to its antioxidant, anti-inflammation, and anti-apoptotic properties. This study aimed, for the first time, to assess the supplemental dietary CUR effects on Baladi bucks’ reproductive performance in the non-breeding season. Ten Baladi bucks were used and allocated to two groups: the CON group received the basal diet only (n = 5); and the CUR group received the basal diet supplemented with CUR (200 mg/kg diet; n = 5) daily for six weeks. Testicular hemodynamics [TH; resistive index (RI), pulsatility index (PI), end-diastolic velocity (EDV), peak systolic velocity (PSV), and colored area toward the testes/pixels(CA)], testicular traits [testicular volume (TV) and echotexture (TE)], reproductive hormones [FSH, LH, testosterone (T) and estradiol 17β (E2)], nitric oxide levels (NO), and semen quality [mass motility (MM; score 0–5), progressive motility (PM%), normal sperm (NS%), viability (SV%) and sperm concentration (SC × 10⁹/ml)] were evaluated. The examinations were started one week before CUR dietary inclusion (W-1) and continued once weekly until two weeks after the CUR withdrawal (W0–W8). Significant (P < 0.001) improvement was recorded in TH (RI, PI, EDV, PV, and CA) from W3 to W5 in the CUR group compared to the CON group. Testosterone and NO levels significantly (P < 0.001) increased in the CUR group in relation to the CON group; whereas E2, FSH, and LH were not affected by supplementation of CUR. Marked improvements (P < 0.01) in the semen quality parameters were noted in the CUR group. A significant increase in TV and a decrease in TE (P < 0.01) was recorded in the CUR group compared to the CON group. In conclusion, dietary supplementation of CUR at a 200 mg/kg diet improved the reproductive performance of Baladi bucks in the non-breeding season as evidenced by significant improvement of testicular hemodynamics, testosterone, and NO levels and semen quality.