Echotexture of testes and epididymides from 10 slaughtered male buffaloes was studied. Diameter of testis and mediastinum testis was measured by ultrasound and compared with respective values taken by calipers. Testes and epididymides of 10 fertile and 10 infertile breeding bulls were examined in vivo through manual palpation and ultrasound imaging. Semen quality of these bulls was also monitored. There were significant (P<0.01) positive correlations between ultrasound and calipers values of all parameters. The testicular parenchyma of fertile bulls was uniformly homogeneous and moderately echogenic. Epididymal tail was more heterogeneous and less echogenic, while epididymal head was homogeneous and less echogenic, than the testicular parenchyma. The epididymal body appeared as hypoechoic structure with echogenic margin. Among 10 infertile bulls, nine had poor semen quality, while one bull failed to give any ejaculate. On ultrasonography, six bulls showed abnormalities in their scrotal echotexture. Among these, one had an abundance of hyperechoic areas scattered in the testicular parenchyma, some of these showed acoustic shadowing, showing testicular degenerations with mineralization. The second bull showed many anechoic areas in the testes and epididymal head, demarcated from the rest of the organ by well defined margins. In the third bull, three-fourth of the right testis showed hyperechoic areas, suspected of testicular degeneration with mineralization. The fourth bull had two anechoic areas in one testis assumed to represent dilated blood vessel. The fifth bull showed small hyperechoic areas within the testicular parenchyma. The sixth bull showed an anechoic area with distinct hyperechogenic margin below the testicular tunics. The remaining four bulls had normal echogenicity of testes and epididymides in spite of poor semen quality. In conclusion, diagnostic ultrasound may be included in breeding soundness examination of breeding bulls.

Key words: Buffalo; Cattle; Fertile Bulls; Infertile Bulls; Ultrasonography