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Breeding soundness exams important for profitability

by Wyoming Livestock Roundup

Gillette – “A poor quality ram will cost producers more than the cost of a breeding soundness exam (BSE),” said Wyoming State Veterinarian Jim Logan at the Northeast Wyoming Sheep Symposium, held Sept. 4 in Gillette. 

“An infertile ram may still possess a robust libido and can prevent fertile rams from covering ewes,” he explained. “This results in a longer breeding season, a longer lambing season and an uneven lamb crop with a reduced average weaning weight.”

BSEs, which examine the conformation, overall health and semen quality of rams, can help reduce costs in an operation. Logan noted that the detrimental effects, in addition to the expense of keeping an infertile ram, justify the expense of a BSE.

Logan explained that BSEs include a physical examination with palpation of reproductive organs, semen evaluation and an Enzyme-Linked Immunosorbent Assay (ELISA) test.

During the physical examination, veterinarians palpate the penis and testicles of the ram.

“It is imperative to ensure the penis can extend, otherwise the ram will not be valuable as breeding stock,” Logan stated. “Without the ability to extend the penis, rams are unable to breed the ewes. This problem is more prevalent in older rams, but younger rams can also have this problem.”

The testicles are palpated for abnormalities such as swelling, sponginess and epididymitis. 

Scrotal circumference is also measured. Research has shown that rams with a greater scrotal circumference produce progeny with greater ability to reproduce and ewes that produce more milk.  

Fertility of the ram is determined by semen evaluation.

“Semen is collected by inserting a lubricated probe into the rectum of the ram. The probe massages the seminal vesicles and electrically stimulates the ram to ejaculate,” Logan stated. 

Once the semen is collected, a sample is placed on a microscope slide and evaluated. Forward motility, shape and viability of sperm cells and the presence of pus or abnormal cellular debris are examined. 

“Sperm motility is important in determining if a ram is fertile,” Logan said. “A fertile ram should have highly motile sperm, at least 90 percent normal, live sperm and no white blood cells in the sample. If rams fall short of these standards, they are considered infertile or sub-fertile.”

“The presence of white blood cells or pus in an ejaculate can be an indication of B. ovis infection, especially in older rams,” he explained. “It can also be an indicator of other bacterial infections.”

An ELISA test will confirm if the animal is infected with B. ovis

It is important that rams have both an ELISA test and BSE prior to breeding season to assure optimum breeding efficiency and a clean, disease-free ram as B. ovis can infect ewes and remain viable in a flock if not detected prior to breeding, he commented. 

The feet, legs, teeth and eyes of the animal are also checked to ensure the animal is physically able to breed and to determine if the animal will pass along undesirable traits.

“If a jaw is overshot or undershot, there is a very good chance that it is a genetic trait that will be passed along to the offspring,” he explained. “It is also important to check the overall condition of the ram, including the parasite load,” Logan elaborated. “A ram with a heavy parasite load will have lower or waning energy levels during the breeding season.”

Kelsey Tramp writes for the Wyoming Livestock Roundup. Send comments on this article to

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