Veterinarian Breeding Soundness Exams
Are You Getting a Bang for Your Buck?
Reading Time: 4 minutes
A lot of emphasis is placed on choosing the right does for your goat herd to ensure they will help you meet your production goals. However, if you are also breeding your does, it is essential to choose the right buck. Choosing the right buck is not just a manner of finding a good-looking goat of the desired breeding. It is also essential that the buck you select can perform his job well. So, how does one know if a buck can breed well? Enter the breeding soundness examination.
A breeding soundness exam is a thorough assessment of a breeding buck performed by your veterinarian to ensure that they can perform their job and meet your herd goals. This examination has several components — the physical examination, the semen evaluation, and infectious disease testing. Carefully discuss your goals with your veterinarian before the exam to ensure that they include all necessary components. Bringing in a new buck may mean that you desire more intensive infectious disease testing. If a buck is expected to breed a large herd of does or navigate a large pasture, he requires a higher degree of fitness. To have the right buck, it is essential to know what you need.
The physical examination is a thorough general examination of the buck. The veterinarian assesses him from head to toe to ensure he can mount and breed. They carefully consider conformation and mobility to ensure that the buck will not be more susceptible to lameness or decreased stamina. They assess the body condition of the buck. Overly fat or overly thin animals will have difficulty breeding. A brief oral exam assesses age and ensures good dentition. Heart and lung are assessments ensure no underlying conditions, such as pneumonia, exist. The external reproductive organs are also thoroughly assessed: The veterinarian palpates the testicles and epididymis to ensure symmetry and appropriate texture, palpates the prepuce, and extrudes the penis to ensure no abnormalities can inhibit function. The scrotal circumference is also measured in adult bucks, as this is an indicator of sperm production. A mature buck should have a scrotal circumference greater than 25cm. This thorough physical examination can indicate abnormalities that can indicate decreased fertility or decreased ability to breed.
The next part of the examination is semen evaluation. Semen can be collected from bucks by use of an artificial vagina or by use of an electroejaculator. Collection with an artificial vagina provides a high-quality semen sample but requires an in-heat doe to stimulate the buck. An electroejaculator can be used without a doe present but does give a lower-quality sample. Due to its ease of use, electroejaculation is most common for semen collection. Once collected, the semen must be kept at a warm temperature, 98 degrees F, to prevent damage before evaluation. Veterinarians then evaluate semen grossly and microscopically. Grossly, it should be cloudy white, with no contamination with urine or blood. Microscopically, veterinarians assess the semen for motility, or forward motion. Bucks should have greater than 50% of the sperm possessing progressive or forward motility. The semen is also assessed for sperm morphology or anatomy. Seventy percent or greater of the sperm cells must be anatomically normal for the buck to have acceptable fertility. The semen evaluation ensures that a buck not only looks healthy but is also sufficiently fertile. Using a buck with poor semen quality will result in a reduced breed-up of does.
The last part of the breeding soundness exam is testing for infectious diseases. When bringing in any new animals to your herd, you want to ensure that a buck will not share any unwanted diseases when breeding your does. Conditions tested depend entirely on the goals of the herd they are entering. It is highly recommended to test for chronic diseases, such as caseous lymphadenitis and caprine arthritis and encephalitis. Johne’s disease may also be tested for at this time. It is also wise to assess for internal parasites before bringing in new animals, particularly in herds battling parasite resistance to common dewormers. It is advisable to perform a fecal assessment on new bucks before contact with your herd. Many breeders will have these tests performed before the sale of the buck; however, some farms may not pursue these tests.
Breeding soundness exams are not just for bucks that are new to your herd. It is also wise to test your bucks every year to ensure they are continuing to be fertile and productive members of the herd. Decreased fertility can result in lower pregnancy rates of does as well as prolonged kidding intervals.
Bucks require year-long care to provide services for a short breeding season. No one wants to discover that they have been caring for an animal that cannot perform its job well. Having your veterinarian perform a breeding soundness exam will ensure that you get the most bang for your buck.
Originally published in the November/December 2021 issue of Goat Journal and regularly vetted for accuracy.