Ultrasonographic evaluation of normal boar testicles.

: The testicles of 14 Landrace boars (7 at 9 months of age and 7 at 15 months of age) were measured and examined by routine physical examination. Semen analysis was done. The testicles were then examined and measured by B-mode ultrasonography. The ultrasonographic appearance and measurements were compared with the physical measurements and the semen analysis. Seminiferous epithelial area (SEA) data were obtained after the testicles were surgically removed. These data were compared with the ultrasonographic data and the other physical data. A correlation could not be found between semen analysis and either physical or ultrasonographic data or between SEA data and semen analysis. Significant differences were found between the 9-month-old and the 15-month-old boars relative to 5 measurements: SEA, tunica albuginea thickness, testicular diameter, testicular length, and epididymal diameter. A ratio of 4:1 was found between each of the average physical measurements (scrotal diameter, testicular-epididymal circumference, testicular-epididymal length) and ultrasonographic measurements of testicular diameter. A ratio of 2.6:1 was found between testicular diameter and epididymal tail diameter (cranial to caudal).