A heron sitting on the back of a buffalo in Vijayawada. File | Photo credit: The Hindu
In a breakthrough that could change the way India rears buffalo and improve dairy productivity, scientists at the National Institute of Animal Nutrition and Physiology (NIANP) in Bengaluru under the Indian Council of Agricultural Research (ICAR) have developed a ready-to-use, egg-yolk-free solution – CRYODIL – with a shelf life of 18 months at brazilo temperature.
Buffalo sperm cryopreserved with CRYODIL showed significantly higher progressive sperm motility after thawing compared to traditional sperm.
It is said to be the first time such a product has been developed and tested in India to offer a safer and longer lasting alternative to traditional methods.
The researchers explained that until now, the sperm of “elite” buffalo bulls had been preserved using egg yolk-based solutions. Although these sperm extenders are widely used, they have several limitations.
The egg yolk must be fresh because its shelf life is only a few hours and its composition varies between eggs, leading to unpredictable results in sperm survival and movement after freezing. Egg yolks can also carry harmful microbes that pose a risk to animal health, and the process of separating the yolk from the white is cumbersome.
In addition, egg yolk contains unknown factors that may reduce sperm motility, making successful fertilization less likely. Although yolk-free attachments are available for cattle in some foreign countries, they are expensive and till now there was no commercially available yolk-free attachment for cattle or buffaloes in India, explained NIANP officials.
Freshly collected mammalian semen consists of semen and seminal plasma, a fluid containing vital components necessary for sperm survival and fertility. During cryopreservation (freezing and storage), semen from a single bull, which is usually only 3 to 5 milliliters, is diluted up to 40-50 times to maximize the number of possible inseminations. This dilution reduces the concentration of seminal plasma components, which threatens the life and fertility of the sperm. Additionally, most of these components are not commercially available and cannot be synthesized artificially, posing a significant challenge to effective sperm preservation, officials said.
To solve this problem, the ICAR-NIANP team investigated whether a natural body fluid from the same or similar species could replace the egg yolk and supply the necessary components. Their research led them to milk from female cattle or buffaloes. While milk contains caseins and whey proteins, not all components were suitable for buffalo sperm. For example, casein proteins did not support sperm viability. After extensive experimentation, scientists discovered that purified whey proteins without milk sugars can maintain the viability and motility of buffalo sperm even after freezing.
Based on this discovery, the team developed CRYODIL, an egg yolk-free sperm extender that is ready to use and has a shelf life of up to 18 months. The product was tested on 24 buffalo bulls and the results were significant. Sperm preserved with CRYODIL showed improved post-thaw sperm motility (how actively sperm can swim after freezing and thawing, which is a key factor in determining whether insemination will result in pregnancy) and viability, which are critical factors for successful fertilization.
In addition to improving sperm quality, CRYODIL is cheaper to manufacture than traditional egg yolk fillers. A patent has also been applied for the product and the method of its preparation. Fertility trials are currently underway at the BAIF Development Research Foundation, Uruli Kanchan near Pune, and once completed, the product is expected to be introduced for commercial use in the area.
Published – 26 Oct 2025 22:27 IST
