CORRELATION OF IN-VIVO TESTICLE AND SEMINAL-VESICLE SIZE WITH POST-MORTEM DIMENSIONS IN BULLS

This study was conducted to quantify the relationships between in vivo measurements of testicular and seminal vesicle size and post mortem s ize of these organs in 30 Santa Gertrudis bulls. The in vivo measureme nts of testicles were obtained by transrectal ultrasonography and palp ation per rectum, while scrotal circumference was measured by scrotal tape. Linear post mortem dimensions were obtained by direct measuremen ts of the excised organs. Volume was assessed by water displacement wh ile the testicles were weighed. Seminal vesicle length, determined by palpation, had the highest correlation with post mortem measurements ( r = 0.70; P = 0.0001). Accurate estimation of the thickness of the ves icles (1.47 vs 1.55 cm for in vivo and post mortem, respectively) was performed by ultrasonograph. Of all seminal vesicle linear measurement s, width had the highest correlations with volume measured by water di splacement (r = 0.67; P = 0.0001 and r = 0.38; P = 0.04 for post morte m and in vivo, respectively). Testicular diameter was accurately measu red by ultrasonography (5.54 vs 4.58 cm in vivo and post mortem, respe ctively) and was highly correlated (range r = 0.84 to 0.89; P = 0.0001 ) with post mortem measurements of testicular volume, weight and circu mference. The correlation between scrotal circumference and diameter o f the testicle was 0.75 (P = 0.0001). The correlations of testicular d iameter measured by ultrasound with the post mortem measurements of te sticular weight and circumference were similar to the correlations bet ween scrotal circumference and those 2 post mortem measurements. We co nclude that palpation of vesicle length is highly correlated with volu me of the seminal vesicle in situ. Individual linear measurements do n ot seem to be an accurate predictor of the relative size of the semina l vesicle. Furthermore, ultrasonography does not seem to be a more acc urate measure of testicular size than scrotal circumference for evalua tion of breeding soundness.