Doppler Waveform Alterations of the Supratesticular Artery and Associated Semen Biomarkers in Infertile Male Dromedary Camels

Male infertility in dromedary camels lacks objective diagnostic tools. This study evaluated the combined diagnostic value of testicular Doppler ultrasonography and semen biomarkers in 68 infertile (azoospermic, <i>n</i> = 21; oligozoospemic, <i>n</i> = 47) and 9 fertile male camels. All animals underwent a breeding soundness evaluation; computer-assisted semen analysis; color Doppler of the supratesticular artery; and a seminal plasma assessment for semenogelin I (SEM I), semenogelin II (SEM II), extracellular matrix protein 1 (ECM1), and testis-expressed protein 101 (TEX101). Infertile camels showed significantly impaired semen quality (<i>p</i> < 0.001). All four biomarkers were significantly lower in the infertile groups than controls (<i>p</i> = 0.001). Doppler indices indicated impaired testicular perfusion, with higher resistive and pulsatility indices (<i>p</i> = 0.003; <i>p</i> = 0.009) and lower velocity parameters (<i>p</i> < 0.001) in infertile animals. Biomarkers were strongly intercorrelated and negatively correlated with Doppler indices. ECM1 was the only significant predictor of infertility from the regression analysis (<i>p</i> = 0.031). Among the oligozoospemic camels stratified by motility, the >50% motility group had significantly higher SEM I and SEM II concentrations (<i>p</i> < 0.002). Integrating Doppler ultrasonography with biomarker profiling provides complementary diagnostic indicators for male camel infertility.