Breeding Soundness Examination of Bucks

BySylvia J. Bedford-Guaus, DVM, PhD, DACT, Peekskill-Cortlandt Veterinary Hospital, Westchester Veterinary Associates
Reviewed/Revised Nov 2023

    There are no specific guidelines for the breeding soundness examination (BSE) in bucks, and guidelines are typically extrapolated from those in rams. Bucks should be tested for Corynebacterium pseudotuberculosis and caprine arthritis-encephalitis virus. The testes should be palpated carefully. Brucella ovis infection is rare; however, sperm granulomas are frequently related to the polled intersex (XO/XY) condition; these are most often found in the head of the epididymis. Cryptorchidism is also common and heritable in Angora goats; as in other species, cryptorchid bucks should not be used for breeding. Testicular degeneration is a common cause of fertility loss in older bucks.

    Breeding Soundness Examination of Bucks
    Scrotum, goat
    Scrotum, goat
    Normal scrotum of a buck. Note the prominent tails of the epididymides in the most ventral portion of the scrotum.

    Courtesy of Dr. Sylvia Bedford-Guaus.

    Measurement of scrotal circumference, goat
    Measurement of scrotal circumference, goat
    Photograph of measurement of scrotal circumference in the buck.

    Courtesy of Dr. Sylvia Bedford-Guaus.

    Semen collection, goat
    Semen collection, goat
    Photograph showing semen collection by electroejaculation in a sedated buck in lateral recumbency. The electroejaculato... read more

    Courtesy of Dr. Sylvia Bedford-Guaus.

    Bucks tend to vocalize excessively if semen is collected via electroejaculation. Therefore, this is preferably done under sedation. Bucks can be easily trained to semen collection using an artificial vagina, and hence this is the preferred method of semen collection in this species. This is performed using an estrous doe, although nonestrous does have also been used. Parameters for semen evaluation are similar to those for rams. Because the ejaculate is typically collected with an AV, sperm production may be measured rather than estimated from scrotal circumference. Semen volume should be 0.5–2 mL, and concentration 1.5–4 billion sperm per mL.

    In general, a buck is deemed a satisfactory breeder if it displays normal physical exam parameters, is free of infectious diseases and devoid of genital lesions, and produces semen with at least 50% progressively normal and 70% morphologically normal spermatozoa.

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