Testicular ultrasound as a breeding soundness examination and biometric tool for West African dwarf buck goats

Abstract

This study was carried out to evaluate testicular ultrasound as a breeding soundness examination (BSE) and biometric tool for West African dwarf (WAD) buck goats. Twelve bucks of proven breeding capability were selected for this purpose. Scrotal circumferences of these animals were measured using a flexible tape. Testicular ultrasound was carried out on the transverse and longitudinal planes on the right and left testes. The electronic caliper on the ultrasound machine was used to measure the testicular length, height and width from which the testicular volume was calculated using the prolate ellipsoid formula (PEF), the prolate spheroid formula (PSF) and the Lambert formula (LF). These were compared with the true testicular volumes obtained by the water displacement method (WDM). Results showed that the mean scrotal circumference was 17.48 ± 0.31 cm. Testicular echo-texture revealed homogenously greyish parenchyma with hyper-echoic mediastinum line in the middle. The scrotal wall appeared as a hyper-echoic semi-circular border line at the caudo-dorsal portion of each testis. The heads of the epididymides of the right and left testes appeared as a small roundish hypo-echoic structure on the caudo-ventral and cranio-ventral portions of each testis respectively. Results of the parameters taken using the electronic caliper revealed that the mean width of both testes was 7.24 ± 0.16 cm. There was a high correlation between scrotal circumference and width of both testes measured on the ultrasound machine. There were no statistically significant differences between the means of the left and right testes length, height and width. Similarly, differences were not statistically significant in the testicular volumes obtained using the PEF and WDM. However, the testicular volumes obtained using the PSF and LF were significantly higher than the true testicular volumes obtained using the WDM. PEF was the best of the three formulae in estimating WAD buck testicular volume. In conclusion, we suggest that testicular ultrasound will be valuable in the BSE and in measuring the important biometric parameters in WAD buck goats.