Читать книгу Bovine Reproduction - Группа авторов - Страница 241

Inability to achieve or maintain penile erection (impotentia erigendi) precludes natural service. A history of failure to impregnate females in the breeding pasture or observation of unsuccessful breeding is often the presenting complaint. A well‐taken history including previous breeding performance, breeding injuries, and the owner's description of the appearance of the bull at the time of attempted coitus are valuable, but observation of the penis during an attempt at erection is a required element for diagnostic evaluation. Use of the electroejaculator to induce erection may be useful but a controlled test mating is preferred.

Because painful stimuli from the spine, rear limbs, or pelvis may interfere with the willingness or ability of the bull to achieve erection and complete the breeding act, a physical examination of the bull at rest and in motion is mandatory. Appropriate management or correction of painful musculoskeletal and spinal conditions may be useful and return some bulls to breeding soundness.

True erection failure may involve disruption of vascular components of the erection mechanism or failure of the corpus cavernosum to fill completely.