What Is a Breeding Soundness Exam?

Profitability in cow-calf production begins with high pregnancy rates and calves born on time in spring. A key element to ensuring this success is having bulls that detect and service cows during estrus.

A breeding soundness exam is an effective way to evaluate the health of your bulls. It goes beyond simply using semen tests and includes five crucial components – physical examination, scrotal circumference measurement, vision testing, reproductive organ health checks and sperm morphology assessments.

Physical Examination

A Breeding Soundness Exam (BSE) is an integral component of horse breeding success. A BSE assesses a potential mare’s ability to conceive, carry and deliver healthy foals successfully; usually veterinarians perform at least one such exam each year before or during breeding season – this examination is similar to a general physical but focused more closely on feet and legs.

Bull examination involves conducting a careful physical exam centered around their reproductive tract (testicles, epididymis, penis and prostate). Semen sample collection and evaluation provide valuable data that allows veterinarians to assess a bull’s ability to breed cows at sufficient rates for high pregnancy rates.

Many herd managers believe a breeding soundness exam (BSE) serves as a fertility check; this assumption is inaccurate as BSE results only apply on the day of examination; any insult or damage to reproductive tract may dramatically change results of BSEs.

As with BSEs, BSEs don’t accurately reflect libido. A stallion may act like a fertile bull but be incapable of consistently breeding cows over an entire breeding season. A good breeding herd should have enough bulls that each can breed and inseminate enough cows for effective reproduction.

An exam to evaluate breeding soundness aims to identify infertile or subfertile bulls that should not be introduced into a herd, enabling herd managers to select bulls with greater chances of successfully breeding and inseminating cows, thus increasing profitability by minimizing dead calves.

Semen Evaluation

An examination for male and female breeding soundness requires physical evaluation. We assess overall condition as well as feet, legs, body structure and penis/sheath lacerations/stricture/swelling in these examinations. Bulls must be in optimal physical condition in order to produce quality semen which allows them to successfully mate and produce calves.

At semen evaluation, a sample of bull’s semen is collected via electroejaculation and carefully evaluated under a microscope for its motility and cell morphology. Sperm cells must move rapidly in an ordered pattern in order to qualify as quality semen samples.

Additionally, sperm cells are evaluated for their morphology (normal or abnormal cell anatomy). A bull to achieve a high rating on semen evaluation must have more than 30% normal sperm present and may need additional staining in order to provide more detail of its contents.

Bacteria are collected from scrotal fluid, urethra, urethral sheath or prepuce for testing to ascertain whether any bacteria transmitted from the stallion to mare could affect fertility issues in their offspring. Common isolates include Pseudomonas, Klebsiella pneumoniae and beta-hemolytic strep (Streptococcus zooepidemicus). Unfortunately, breeding soundness examination cannot evaluate nonphysical factors like libido or social dominance. Bulls with low libido may pass, yet will fail when matings with herd cows resulting in poor breeding success and matings being unsuccessful compared with their peers in terms of successful matings in breeding soundness exam results.


Attracting cows and breeding them are vitally important aspects of success for any herd, yet less than 20% of producers in the US conduct breeding soundness exams on their bulls prior to spring turnout. This missed opportunity allows you to ensure that your herd’s bulls can perform effectively for your breeding herd in coming seasons.

A breeding soundness exam involves an evaluation of a bull’s physical structure, reproductive organs and semen. It is crucial to inspect penis, testicles and vesicular glands for any anomalies which might impede production of viable semen and produce viable eggs for breeding cows successfully. Furthermore, the scrotum should also be evaluated in order to ensure free of injuries or diseases which might interfere with successful mating between bulls and cows.

Bulls’ vision plays an essential role in their ability to breed. He must have the ability to quickly switch his fixation between objects in his field of vision while remaining stable, which enables them to correctly locate and mount cows in pastures. Furthermore, seeing semen from across a pasture allows bulls to collect it for use by cows.

Breeding soundness exams provide an ideal opportunity to assess a bull’s vision. A qualified veterinarian can help evaluate any eye diseases, injuries or any other issues which could hamper his ability to mount and serve cows effectively.

Reproductive Organs

An examination of a male animal’s genitals is one of the best ways to evaluate breeding soundness. This exam includes evaluation of their libido and mating ability as well as an inspection of both internal and external reproductive organs as well as collection of semen.

Heifers that are sexually mature and cycling prior to breeding season have greater odds of quickly becoming pregnant and experiencing higher fertility throughout their productive lives than heifers that are immature or identified as not reproductively sound through palpation. This factor becomes even more significant for herds that use embryo or oocyte donations where pregnant heifers need to maximize the value of donated material.

A bull breeding soundness exam is an objective way of evaluating fertility in bulls, as well as detecting issues that require long-term or immediate attention. The Society for Theriogenology currently defines four criteria for breeding soundness exams: physical exam, minimum scrotal circumference by age of the bull, minimum progressive motility and 70% normal cells in his sperm morphology sperm samples; using these standards it’s possible to clearly identify infertile or subfertile bulls; also this provides a good estimate of probability of pregnancy as well as days until weaning.

Stocking Rate

A stocking rate measures the number of cows needed for breeding by each bull during each breeding season. On average, 25 mature bulls and 15 yearling bulls per mature bull require to produce viable offspring; higher stocking rates increase the likelihood of cows missing their first heat and having late pregnancies; unlike breeding soundness exams however, stocking rate tests don’t assess bull libido or willingness to breed.

An effective cow-calf operation hinges on bulls being able to recognize estrus females, service them and produce high quality sperm for fertilizing the waiting egg. A breeding soundness exam provides insight into any limitations in these capabilities and helps producers make management decisions to increase chances of success in their herds.

Numerous factors impact a bull’s fertility, such as his scrotal circumference and semen production. A bull with a larger-than-recommended scrotal circumference is considered poor breeding potential as they do not produce sufficient amounts of high-quality semen to breed with. Furthermore, their size correlates directly to when their female offspring enter puberty.

Another element affecting sperm quality is testicular mass, which can be measured through measuring scrotal circumference. A larger scrotum means more daily production of high-quality sperm; moreover, this indicator also correlates to an animal’s breeding abilities and libido.

The breeding soundness exam includes a physical examination (feet, legs, eyes and teeth), palpation and grading of reproductive tracts and semen evaluation to measure sperm cell motility. To be considered an acceptable potential breeder a minimum of 30% individual progressive motility and fair gross motility is necessary.