Biometric Indicators, Testicular Parameters and Semen Characteristics in Peripubertal and Postpubertal Pleven Blackhead Rams

The aim of this study was to investigate basic biometric indicators, testicular parameters, semen characteristics and testicular parenchymal echogenicity in peripubertal and postpubertal Pleven Blackhead rams. The animals were separated in two groups: group I (peripubertal rams, aged 5 - 8 months; n=8) and group II (postpubertal rams, aged 14 - 22 months; n=8). The biometric indicators age, body weight and scrotal circumference were determined by the routine methods. Semen was collected by electroejaculation and evaluated for volume of ejaculate, concentration of the spermatozoa and mass motility. Transversal diameters of the testes were measured by the electronic calipers of the ultrasound scanner. Testicular parenchymal echogenicity and pixel heterogeneity were assessed by measuring numerical pixel values (NPVs) and standard deviation of NPVs using Image ProPlus 7.0 analytical software. The results were statistically processed by t-test and correlation analysis. The current study indicated significantly (P < 0.05) higher mean values of scrotal circumference (30.7 ± 4.4 cm vs. 18.8 ± 5.9 cm), total transversal diameter (5.1 ± 0.5 cm vs. 2.9 ± 0.94 cm) and testicular parenchyma echogenicity (110.4 ± 14.2 vs. 74.8 ± 32.5) in postpubertal than peripubertal rams, but no effect of these parameters on concentration of the spermatozoa and mass motility was found. The age and the body weight correlated positively (P < 0.05) to scrotal circumference and total transversal diameter. Testicular parenchymal echogenicity showed a strong positive relationship (R = 0.92; P < 0.05) with pixel heterogeneity. In conclusion, the period between peripubertal and postpubertal age in rams is associated with significant alterations of scrotal circumference, transversal diameter of the testes and testicular parenchymal echogenicity with no effect on concentration of the spermatozoa and their mass motility. Computer-assisted quantitative analysis of the testicular echotexture may be introduced in a system for early assessment of the sexual maturity in rams.