Читать книгу Bovine Reproduction - Группа авторов - Страница 233

Deviation of the penis results in inability to copulate. Affected bulls may have a history of one or more successful breeding seasons and there is often no history of trauma or penile injury. In the bull the dorsal apical ligament of the penis originates from the tunica albuginea proximal to the free portion of the penis, runs along the dorsum of the free portion beneath the penile skin, and rejoins the tunica albuginea near the distal end of the CCP. The ligament inserts on the distal penis centrally with a broad set of fibers and on the left lateral aspect of the free portion of the penis with a narrower and better defined set of fibers [9, 30]. This ligament gives support to the erect penis and maintains the normal alignment of the penis as the bull positions himself for coitus and utilizes the tip of the penis to search for the vulva. Following intromission and achievement of peak erectile pressure the ligament may “slip” to the left and the distal penis will often assume a corkscrew shape and spiral within the vagina at the time of the ejaculatory lunge [6]. When erection is induced with the artificial stimulus of an electroejaculator, the penis will frequently assume this same spiral orientation, often prior to ejaculation.