HIPPEX CRYO is a new liquid medium to freeze stallion sperm cells. The liquid medium has several unique characteristics.
The first unique feature is that no egg yolk is used as a cryoprotectant. Egg yolk, but especially the fraction of egg yolk consisting of low-density lipoprotein particles, has until now been an essential ingredient in stallion semen freezing because it offers three ways of protection against the freezing and thawing process. The concentration of egg yolk or egg yolk fraction in freezing media differs per animal species and is related to the type of sperm and the molecular mechanisms underlying the protection. HIPPEX CRYO contains lipoprotein particles with a similar molecular structure to egg yolk low density lipoprotein particles, but the main components come from plant seeds. The different components have been chosen in such a way that the protective effect is optimal for stallion semen and are produced using a proprietary technology.
The use of egg yolk entails biosecurity risks. This means that certain infectious pathogens can be spread via egg yolk. The transport of egg yolk or egg yolk components is therefore experiencing more and more restrictions. Obviously,there is a strong need of elimination of animal products from media for semen preservation to comply with international regulations on import and export. HIPPEX CRYO might serve here as an excellent alternative.
The second unique feature is the possibility to sell the product HIPPEX CRYO as a powder. An advantage is that powder is easy to transport at ambient temperature all over the world without loss of quality. Furthermore, the shelf life of the product is at least 2 years when stored at 4 °C.
A third unique feature is that HIPPEX CRYO has an equal or better performance than a standard egg yolk freezing medium. After internal testing, HIPPEX CRYO was first successfully tested externally at Holstud (Jorgen van der Holst) in Lunteren (NL) and thereafter at the Paul Schockemöhle Stud farm in Mühlen (Germany). Bart Kools and his coworkers performed 72 tests on ejaculates from 6 different stallions. A commercial egg yolk medium was used as a reference.
With regard to motility of the sperm cells after freezing and thawing, HIPPEX CRYO was found to have an equal performance for 1 stallion and a higher one for 5 stallions. The higher motility values ranged between 5 and 15% higher compared to the reference egg yolk medium.
With regard to the viability of the sperm cells after freezing and thawing, a higher value was found for HIPPEX CRYO in all stallions. Depending on the stallion a higher value between 4 and 21% motility was found when compared to the egg yolk containing reference.
It is expected that the fertility after freezing/thawing with HIPPEX CRYO is higher than with the use of an egg yolk containing medium because there is a strong correlation between progressive motility and pregnancy rate. This was also found earlier for HIPPEX, which is used as a medium to keep semen chilled. This was found during more than 5 years of use of HIPPEX by Bart Kools on the Paul Schockemöhle Stud farm. When quality for the customer is your priority, then HIPPEX is the choice to use as fresh extender.
HIPPEX CRYO is part of the HIPPEX series semen preservation media that are produced and sold by HuVeSearch bv (Pelt, Belgium; www.huvesearch.com )
