Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
Anim Reprod Sci. 2012 Oct;134(3-4):135-40. doi: 10.1016/j.anireprosci.2012.08.025. Epub 2012 Aug 23.
The objectives of this study were to characterize development of the testicular vascular cone using ultrasonography and to determine associations of vascular cone morphology with scrotal temperature, semen quality, and sperm production. Beef bulls (n=70) were examined from 10 to 70 wk of age in two years, and a third group of bulls (n=44) was examined only at 74 wk of age. Testicular vascular cone diameter increased until approximately 13.5 mo of age, or until 1 to 8 wk before maximum scrotal circumference was observed. Vascular cone fat thickness also increased with age and followed a pattern similar to that observed for backfat. Testicular artery wall thickness and the distance from the arterial to the venous blood in the vascular cone decreased with proximity to the testis. Vascular cone diameter was negatively correlated with scrotal surface temperatures and with the percentage of sperm head defects and detached sperm heads, but positively correlated with the percentage of normal sperm. The arterial-venous blood distance was negatively correlated with the percentage of normal sperm and positively correlated with percentage of sperm head defects and proximal droplets. In conclusion, testicular vascular cone diameter increased with age following testicular development, whereas vascular cone fat thickness increased similar to a pattern observed for backfat. Increased testicular vascular cone diameter and decreased distance between arterial and venous blood were associated with increased percentage of normal sperm and decreased percentages of sperm defects.
本研究的目的是通过超声检查描述睾丸血管圆锥的发育情况，并确定血管圆锥形态与阴囊温度、精液质量和精子生成的关系。在两年内，对 70 头公牛从 10 周至 70 周龄进行了检查，第三组 44 头公牛仅在 74 周龄时进行了检查。睾丸血管圆锥直径在 13.5 个月左右或最大阴囊周长观察前 1 至 8 周之前一直增加。血管圆锥脂肪厚度也随年龄增加而增加，其模式与背脂相似。睾丸动脉壁厚度和血管圆锥内动脉到静脉血的距离随与睾丸的接近而减小。血管圆锥直径与阴囊表面温度以及精子头部缺陷和脱落精子头的百分比呈负相关，但与正常精子的百分比呈正相关。动静脉血的距离与正常精子的百分比呈负相关，与精子头部缺陷和近端液滴的百分比呈正相关。总之，睾丸血管圆锥直径随睾丸发育而随年龄增加，而血管圆锥脂肪厚度的增加与背脂的增加模式相似。增加的睾丸血管圆锥直径和动脉与静脉血液之间的距离减小与正常精子百分比增加和精子缺陷百分比减小有关。
