In rams, the breeding soundness examination (BSE) is performed much as for bulls, beginning with a thorough physical examination that focuses on general soundness and the external genitalia. Healthy rams should be alert, free of lameness, display a uniform fleece, and be free of wounds, abscesses, or injuries. Body score is classified as 1–2, underconditioned; 3–4, optimal; and 5, overconditioned. Underconditioned and overconditioned rams are undesirable. The scrotum is examined as described above for bulls, with the same anatomical orientation of testes and epididymides.
Courtesy of Dr. Sylvia Bedford-Guaus.
Any major abnormalities of the external genitalia or lumps or irregularities of the testes or epididymides render the ram unsatisfactory. Infectious epididymitis is the most common genital pathology identified in rams. Ram epididymitis affects old rams and is primarily due to Brucella ovis. Lamb epididymitis, which affects prepuberal lambs, is due to Actinobacillus seminis. In both cases, the endpoint is the development of sperm granulomas which render rams infertile (bilateral) or subfertile (unilateral). Hence the importance of thorough palpation of the epididymides during a BSE and the culling of affected animals. An ELISA test for B ovis should be done on range rams and rams > 9 months old. Because not all infected rams display epididymal lesions, this is considered the preferred way to screen for and eliminate the disease from flocks. A positive test renders the ram unsatisfactory. (Also see Ram Reproductive Management.)
As in bulls, the measurement of scrotal circumference (SC) is considered a good estimate of sperm production potential and quality. Scrotal circumference should be ≥ 30 cm for rams 8–14 months old (> 36 cm is exceptional) and ≥ 33 cm for rams > 14 months old (> 40 cm is exceptional).
Semen is most commonly collected by electroejaculation using a "ram probe." Sperm motility can be evaluated grossly (wave-like motion) or individually (as for bulls). Motility and morphology of individual spermatozoa is evaluated as for bulls, with > 70% progressive motility being exceptional, > 30% satisfactory, and < 30% unsatisfactory. The percentage of morphologically normal sperm should be > 70%. Presence of > 5 WBCs per high power field is questionable (WBCs are correlated with B ovis infection).
For a ram to be considered satisfactory, it must meet all the minimal requirements of general health, body condition score, and scrotal circumference, and produce semen with a minimum of 30% progressively motile and 70% morphologically normal sperm. Questionable rams are those with one questionable or unsatisfactory parameter that may resolve over time, and must be free of infectious disease. Questionable rams should be retested at a later date. Otherwise, rams should be classified as unsatisfactory.
