Animal reproduction
Sperm cell count & viability analysis
The NucleoCounter® SP-100™ is used for sperm cell count and viability of a variety of species. Continue reading to find out how the SP-100™ aids the process of animal reproduction and selective breeding with bulls, boars, equine, canine, ram and other species.
Boar sperm cells
Selective breeding via artificial insemination is widely used to improve the characteristics of swine. Selective breeding favors the promotion of reproductive traits but also influences structural correctness, size, muscle type and allocation, fat cover and capacity. To maximize the chances of a full litter, it is important to have enough—but not too many—sperm cells when inseminating. A sufficient number is typically 2.0 – 2.5 billion cells per 80ml in Europe and more in the Americas.
Using a photometer to estimate sperm count is an outdated but still widely used method. But as it uses an indirect method of measurement, it is prone to interference from dust, debris, and gel particles. Therefore, the coefficient of variance (CV) is usually 10% or more. A high CV means that, due to the high variation, you must pack more cells in the doses produced to ensure they contain a specific number of cells.
The NucleoCounter® SP-100™ is a unique cell counter which improves the credibility of the sperm count in ejaculates as well as extended semen doses and can provide direct economic advantages. Because the CV is below 3%, fewer cells are needed to ensure a specific minimum number of cells present in 95% of samples. Using an extender does not interfere with the instrument’s high precision, as the detection method is direct, making use of propidium iodide (PI) to stain DNA.
On average, a boar ejaculate yields between 10 and 100 billion sperm cells. If each dose contains a minimum of three billion cells in 95% of the sample on average, then the SP-100™ will provide up to 31 doses. However, working with a photometer will only yield 26-27 doses at the same quality standards due to the higher CV of the measurements.
The SP-100™ can also determine the viability of sperm cells. A boar might produce a large quantity of semen but of very low quality, due to many of the sperm cells being dead. Instead of wasting resources on seemingly high-quality boars with low viability sperm cells, focusing on boars producing sperm cells with higher viability maximizes the chances of a full litter by using a count of viable sperm cells instead of the total.
Bull sperm cells
Selective breeding via artificial insemination is widely used to produce the best meat and dairy. For dairy cattle, those that produce high amounts of milk, and have increased protein and lipid content in their cells, have the most desirable traits. Beef cattle, on the other hand, are bred for their size and muscle mass. With insemination, obtaining a certain number of cells for the highest possible chances of successful impregnation is essential.
Although it is an old method, a photometer is still used for estimating sperm count. It uses an indirect method of measurement and is prone to interference from dust, debris and gel particles which can cause the CV to increase to 10% or more. Furthermore, the extender used for bull sperm is most often based on egg yolk, interfering with methods such as photometers when determining sperm cell concentration.
On average, bull ejaculate yields about five billion sperm cells. If each straw is packed with 30 million cells, then the SP-100™ will provide 150-160 straws, whereas working with a photometer will yield only 130 straws, even when meeting the same quality standards, due to the higher CV of the measurements.
Stallion sperm cells
Selective breeding via artificial insemination is the most used breeding method in the horse industry, including racing, showjumping, and for equestrian leisure.
After obtaining the ejaculate, an extender is added to give sperm cells sustenance and to counteract the effects of seminal fluid that carries the sperm cells during ejaculation. If an extender is not added, the seminal fluid may kill the sperm cells.
Though prone to interference from dust, debris and gel particles, the photometer method is still widely used to estimate stallion sperm count. The CV could be 10% or higher with a photometer. Furthermore, the extender used for stallion sperm is most often milk-based, leaving photometers ineffective at determining sperm cell concentration.
With a CV below 3%, the NucleoCounter® SP-100™ is a unique cell counter which improves the credibility of sperm counts in straws. The extender, even if milk-based, does not interfere with the high precision of the SP-100™ since the detection method uses PI to directly stain DNA. Therefore, the instrument can be used to determine the number of cells in the final extended dose.
Stallion semen varies a lot in how well it freezes and is dependent on specific extenders to yield the best results. The SP-100™ will enable you to find the best extender to suit your needs, as the instrument not only provides the total sperm cell count, but also the percentage of living cells.
Dividing a semen sample into multiple aliquots and freezing them with different extenders, followed by viability determination, provides quick and precise results which can raise the success rate of insemination, thus ensuring higher levels of customer satisfaction and better overall results of your breeding programs.
Sperm cell count & viability for other species
The NucleoCounter® SP-100™ is used on a regular basis by customers for the species mentioned above, but sperm cells from other species have also been analyzed with success with the SP-100™.
If your species of interest is not listed, please contact us for additional information on how we might be able to help. We have extensive experience supporting customers who work with diverse samples including canine, deer, ram, cheetah, and even fish!
