The iSperm: A Potential Alternative for On-Ranch Bull Semen Analysis

Makayla Ogg and Carla Sanford

Department of Animal & Range Sciences, Montana State University

Bozeman, Montana

Author Information:  Makayla Ogg is a first year MS student working with Dr. Carla Sanford (corresponding email:


There have been reports that one in every 5 bulls are categorized as “unsatisfactory potential breeders” or subfertile, typically either due to poor semen quality, physical examination concerns, or both (Lagerlof, 1934; Carroll et al., 1963; Elmore et al., 1975). It is estimated that use of subfertile bulls can cost a rancher 50 or more pounds of weaning weight per calf for every 21 days a cow fails to conceive in a given breeding season (Barth, 2007). A breeding soundness exam (BSE) evaluates the physical health and structure of the bull, in addition to several key parameters of the semen collection, set by the American Society for Theriogenology. A BSE is performed to identify any issues that would limit establishing pregnancy in ≥ 25 healthy, cycling females in a 65–70-day breeding season (Kastelic, et al., 2008). The basic recommendations set for the BSE include a minimum of 70% morphologically normal sperm, at least 30% progressive sperm motility, and a minimum scrotal circumference based on age and breed (Koziol and Armstrong, 2018). However, the Western Canadian Association of Bovine Practitioners bull BSE system requires a minimum of 60% sperm motility. In order to assess ability to successfully breed, bulls should be tested before the breeding season, whether the bull has been used in previous seasons or is a new purchase. An annual BSE is critically important to the calf crop of the subsequent year. When looking to purchase bulls for the upcoming breeding season, we should also select those that are of good health and optimum reproductive performance. More recently, producers, researchers, and veterinarians are considering the use of novel technology to provide a more portable, cost-effective, and accurate means of calculating sperm concentration and sperm motility for BSE.

Currently, the hemocytometer or visual evaluation of semen is common practice for veterinarians, seedstock producers, and even some bull testing centers when completing a BSE. This evaluation is dependent upon a trained individual that can accurately access the samples collected, and conclude with a simple pass or fail for the bull while considering the factors listed by the Society for Theriogenology. There are certain semen quality factors that are evaluated during a BSE, including semen concentration, progressive motility, and abnormalities of the sperm. Morphology, or abnormalities of the individual sperm, may include abnormalities with the sperm head, tail, and midpiece. However, with different individuals evaluating the ejaculate at different locations or at different times of collection, there can be variability in the passing of subfertile bulls, or bulls not meeting the standards for a satisfactory evaluation based on concentration, motility, or adequate number of normal sperm cells. The subjective differences can result in the decision of passing or failing of a bull at that time, but there are options for technology that can be used during a BSE that reduce human error.

Historically, academic institutions, large bull testing centers, artificial insemination companies, and other research organizations have utilized equipment and technologies that can be more accurate for assessing and evaluating semen samples. This results in more objective semen assessment for passing a bull and identifying the bulls that are of greater fertility potential, and identifying sires that may have inadequate semen quality. The process of evaluating a semen sample for more precise and accurate determination of bull sperm concentration, viability, integrity and membrane potential of the sperm may occur by the use of a single technology, or a combination, of a computer-assisted semen analysis (CASA), a flow cytometer, or other technologies. Limitations of using more specialized equipment such as CASA can be expensive and not economically viable for some veterinarians or ranches.

In recent years a newer, more affordable technology has come out, the iSperm (Aidmics Biotechnology Co.), which is a mini-iPad application that connects to a small microscope and can evaluate an individual semen collection sample. This technology was developed for use in equine, bovine, ovine, swine, canine, caprine, and murine to measure motility, concentration, linearity, and more. Presently, the iSperm system has been validated in equine but not bovine (Dini et al., 2019; Moraes et al., 2019). When evaluating a semen sample, only a very small amount of sample is required in order to achieve an accurate reading. The most important factors that the iSperm analyzes are the concentration and motility measurements, the technology is able to achieve an accurate reading with the subjectiveness that previous techniques did not allow for, while being a more affordable alternative to the CASA. However, before extensive adoption of this technology takes place, it needs to be further validated in other livestock species, including bulls. Upon validation and accurate analysis of the sample, this technology could potentially be an asset to the beef industry in identifying bulls that may have been categorized as subfertile with traditional BSE procedures. It has been reported that the iSperm has comparative accuracy with that of the NucleoCounter and Androvision, which are other options commonly used for BSE in livestock (Dini et al., 2019). A group at Ohio State University College of Veterinary Medicine indicated that the iSperm meets the standards for the equine industry, and is valuable due to the low cost and effectiveness for on-the-farm analysis of semen (Moraes et al., 2019). Although the equine industry has found this technology to be both affordable and accurate, more research is needed to validate the accuracy of the iSperm in other species.

The iSperm may promote the passing of bulls that have higher quality semen and fewer of the subfertile bulls that would have potentially been passed by traditional evaluations methods. The analysis can be done chute-side at the time of collection, saving the data of each individual bull to the memory of the iPad. Compared to other equipment, this technology is much more affordable, around $2,200 for the software (Jorgenson Vet) that can be used on an existing iPad for use by veterinarians, bull test operations, or ranchers needing a more cost-effective while accurate assessment of semen quality. Regardless of the equipment or technology used, it is critical to perform an annual BSE on bulls to ensure the success of the subsequent calf crop. This exam ensures that any bulls sold or bulls that are going to be used in the upcoming breeding season meet the minimum breeding requirements set by the Society of Theriogenology. With new technology like the iSperm, producers, veterinarians, and researchers can analyze semen right at the chute on a device to determine the quality of semen. So where do we go from here? Before the iSperm can be adopted for use in the beef industry, the technology needs to be further researched and validated before it is extensively used. However, this affordable technology has the potential of being a objective, cost-effective means of identifying bulls that meet the benchmarks of a BSE in the future that ranchers, veterinarians, bull test centers, and researchers could use.

iSperm mCASA software on an iPad system for a portable option of computer-assisted sperm analyzer;

Photo source: iSperm mCASA software on an iPad system for a portable option of computer-assisted sperm analyzer;


Literature Cited

Barth, A. D. 2007. Evaluation of potential breeding soundness of the bull. In: R.S. Youngquist and W.R. Threlfall, editors, Current Therapy in Large Animal Theriogenology 2. Saunders Elsevier, Philadelphia. 228–240.

Carroll, E. J., L. Ball, and J. A. Scott. 1963. Breeding soundness in bulls--a summary of 10,940 examinations. J Am Vet Med Assoc. 142:1105-1111.

Chenoweth, P.J., J. C. Spitzer, and F. M. Hopkins. 1992. A new bull breeding soundness evaluation form. Proc. Ann. Mtng. Soc. for Theriogenology. San Antonio, TX. 63-71.

Dini, P., L. Troch, I. Lemahieu, P. Deblende, and P. Daels. 2019. Validation of a portable device (iSperm®) for the assessment of stallion sperm motility and concentration. Reprod. Domest. Anim. 54(8), 1113-1120.

Elmore, R., C. J. Bierschwal, C. E. Martin, and R. S. Youngquist. 1975. A summary of 1127 breeding soundness examinations in beef bulls. Theriogenology. 3:209–218.

Kastelic, J. P. and J. Thundathil. 2008. Breeding soundness evaluation and semen analysis for predicting bull fertility. Reprod. Domest. Anim. 43(Suppl. 2):368– 373.

Koziol, J. H. and C. L. Armstrong. 2018. Manual for Breeding Soundness Examination of Bulls. Society for Theriogenology. Second Edition.

Lagerlof, N. 1934. Research concerning morphologic changes in the semen picture and in the testicles of sterile and subfertile bulls. Acta Pathol. Microbiol. Scand. Suppl. 19:2

Moraes, C. R., E. E. Runcan, B. Blawut, and M. A. Coutinho da Silva. 2019. Technical Note: The use of iSperm technology for on-farm measurement of equine sperm motility and concentration. Trans Anim Sci. 3(4):1513-1520.