Deparment of Animal Science, State University of Londrina, Londrina, Paraná, Brazil.
Animal Production Laboratory, Animal College of Veterinary Medicine, University of Northern Paraná, Arapongas, Paraná, Brazil.
Reprod Domest Anim. 2021 Jul;56(7):1034-1039. doi: 10.1111/rda.13947. Epub 2021 May 18.
The aim of this study was to compare the biometric testicular characteristics, skin thickness and haemodynamics of the testicular artery of 12- and 24-month-old bulls using Doppler ultrasonography, the study was conducted using 48 indicus-taurus animals. The scrotal circumference (SC) and biometry characteristics of the bulls were measured to calculate the testicular volume. Doppler ultrasonography was used to obtain the haemodynamic values of the testicular artery. The skin thickness and volume were lower (p<.01) in the younger bulls (12 months:4.68 ± 0.68 mm; 168.76 ± 47.96 cm ) versus 24 months (5.05 ± 0.89; 499.73 ± 129.24 cm ) animals (p<.01). During diastole, mean velocity was lower in the 12 months (7.98 ± 3.83) than in the 24 months (11.37 ± 4.15) animals (p <.05). The 12-month-old animals had higher pulsatility and resistivity indices (0.49 ± 0.02; 0.51 ± 0.20) compared to the 24-month-old animals (0.32 ± 0.16; 0.40 ± 0.15) (p < .05). The final testicular end velocity was lower in animals with long/moderate-shaped (L/M) (7.31 ± 2.91) than in those moderate/oval-shaped (M/O) (11.48 ± 3.88) testicles (p < .05). Animals with L/M testes presented higher pulsatility values and resistivity indices (0.51 ± 0.05; 0.55 ± 0.04) compared to animals with M/O shape (0.29 ± 0.20; 0.36 ± 0.15). We showed that the blood flow of the supra testicular artery between the two evaluated ages differed, and that 24-month-old bulls presented better thermoregulation capacity. Animals with a long/moderate testicular format presented a greater vascular resistance, which was imposed on the blood flow due to the anatomical differences in the testicular artery, resulting in lower velocity, and indicating better heat dissipation in this format.
本研究旨在使用多普勒超声比较 12 月龄和 24 月龄公牛的睾丸生物测量学特征、睾丸动脉的皮肤厚度和血液动力学。通过测量阴囊周长（SC）和公牛的生物测量学特征来计算睾丸体积。使用多普勒超声获取睾丸动脉的血液动力学值。12 月龄公牛的皮肤厚度和体积较低（p<.01）（12 月龄：4.68±0.68mm；168.76±47.96cm）与 24 月龄（5.05±0.89；499.73±129.24cm）动物（p<.01）。在舒张期，12 月龄动物的平均速度（7.98±3.83）低于 24 月龄动物（11.37±4.15）（p<.05）。12 月龄动物的搏动指数和阻力指数较高（0.49±0.02；0.51±0.20）与 24 月龄动物（0.32±0.16；0.40±0.15）相比（p<.05）。长/中等形状（L/M）（7.31±2.91）的睾丸终末流速低于中等/椭圆形（M/O）（11.48±3.88）睾丸（p<.05）。L/M 睾丸的动物具有较高的搏动值和阻力指数（0.51±0.05；0.55±0.04）与 M/O 形状的动物相比（0.29±0.20；0.36±0.15）。我们表明，两个评估年龄之间的精索动脉血流不同，24 月龄公牛具有更好的体温调节能力。具有长/中等睾丸格式的动物表现出更大的血管阻力，这是由于睾丸动脉的解剖差异对血流造成的，导致速度降低，并表明在这种格式下更好地散热。
