Until recently, assessing the fertility of breeding bulls has been a complicated and expensive matter, involving laboratory tests of the bulls’ semen. Now, a research team from Cornell University has developed a novel fertility assessment method called RHEOLEX that is quicker and easier to perform than the traditional ones, resembling a home pregnancy test.
The scientists found inspiration in a biological process occurring in mammals called “rheotaxis,” through which the female reproductive tract simultaneously guides and selects high-quality sperm. By mimicking the cow’s female reproductive tract’s dimensions and hydrodynamic features in a microfluidic device, the researchers managed to assess the reproductive quality of bulls’ sperm within just a few minutes.
While traditionally, sperm quality is evaluated using computer-assisted sperm analysis that measures swimming speed and concentration, such a method ignores the strenuous process of sperm moving along the female’s reproductive tract described through the concept of rheotaxis.
“This method, along with the motile (fast speed) sperm concentration determination, can quickly predict fertility levels in artificial insemination,” said study lead author Mohammad Yaghoobi, a doctoral student in Food Science at Cornell. “We can predict the bull’s in vivo sperm fertility level within five minutes.”
According to Yaghoobi, unlike conventional semen quality parameters, which often fail to provide statistically significant predictions, the RHEOLEX method is an easy and accurate biomarker for determining in vivo male fertility.
“We are essentially taking rheotaxis results and translating that into signals that tells us the bull fertility level, which is great, because it can save companies a lot of money by selecting the best bulls. We are using nature’s selection process and that’s a huge difference,” said study senior author Alireza Abbaspourrad, an assistant professor of Food Chemistry and Ingredient Technology at Cornell.
“With this new RHEOLEX method, you can conduct better selection and breeding for bulls and cows, which can translate into higher quality and quantity products like improved milk and meat. This saves breeders and producers time,” she concluded.
The study is published in the journal Lab on a Chip.
By Andrei Ionescu, Earth.com Staff Writer