Seasonal Alterations in Testicular Hemodynamics and Echotexture in Relation to Semen Quality in Buffalo Bulls

The present study is aimed at investigating the usefulness of the pulsed-wave Doppler ultrasonography for the characterization of testicular blood flow in buffaloes during the nonbreeding and breeding seasons. Ten Egyptian buffalo bulls were evaluated for changes in the blood flow (Doppler's indices: resistive index (RI) and pulsatility index (PI)) at the levels of supratesticular (STA) during the breeding (winter) and nonbreeding season (summer). The alterations in testicular parenchyma echotexture (pixel intensity (PIX) and echotexture heterogeneity (EH)) were assessed by computer analysis software. Circulating testosterone and nitric oxide (NO) concentrations and total antioxidant capacity (TAC) were measured colorimetrically. Sperm parameters including total and progressive motility %, viability %, morphology %, and concentrations were assessed. Results revealed lower values (p < 0.05) of RI (0.55 +/- 0.02) and PI (0.82 +/- 0.03) within the STA in the breeding period compared to the nonbreeding period (RI: 0.67 +/- 0.03; PI: 0.99 +/- 0.01). Higher (p < 0.05) PIX and EH were found in the nonbreeding season (PIX: 72.09 +/- 1.81; EH: 14.99 +/- 1.37) compared to the breeding season (PIX: 60.95 +/- 1.51; EH: 11.75 +/- 0.63). Concentrations of testosterone and TAC were not significantly changed. However, the concentrations of NO were greater (p < 0.05) during the breeding season (78.21 +/- 0.87) compared to those of the nonbreeding one (59.74 +/- 2.97). Total motility %, progressive motility %, viability %, and sperm concentrations were higher during the breeding season compared to that during the nonbreeding season (p < 0.05). In conclusion, seasonality alters testicular hemodynamics and echotexture, NO concentrations, and sperm quality in buffaloes without alterations in the testosterone and TAC levels.

Automated summary

The present study aimed to investigate the usefulness of pulsed-wave Doppler ultrasonography in characterizing testicular blood flow in buffaloes during the non-breeding and breeding seasons. The results showed that the breeding season had lower resistive index (RI) and pulsatility index (PI) values compared to the non-breeding season. The non-breeding season had higher pixel intensity (PIX) and echotexture heterogeneity (EH) values. Nitric oxide (NO) concentrations were higher during the breeding season, while testosterone and total antioxidant capacity (TAC) levels did not significantly change. Sperm quality parameters were higher during the breeding season compared to the non-breeding season. In conclusion, seasonality affects testicular hemodynamics, echotexture, NO concentrations, and sperm quality in buffaloes without altering testosterone and TAC levels.