Semen Storage
a) Collection: Semen is collected from a bull using an artificial vagina during mating simulations.
b) Semen Evaluation: The collected semen is evaluated for quality, including sperm count, motility, and morphology.
c) Dilution: Semen is often diluted with a specialized extender solution. This serves to increase the volume, improve viability, and aid in the preservation of sperm cells.
d) Cooling: The diluted semen is rapidly cooled to a temperature of about 4°C (39°F) using a cooling device, such as a water bath or a refrigerator. This slows down metabolic activity and extends the viability of the sperm.
e) Packaging: Cooled semen is packaged into individual straws made of plastic or other suitable materials. Each straw contains a specific volume of semen.
f) Sealing: The straws are sealed to prevent contamination and to maintain a sterile environment for the sperm.
g) Labeling: Each straw is labeled with information such as the bull’s identification, collection date, and other relevant details.
h) Storage: The sealed and labeled straws are placed in storage canisters filled with liquid nitrogen. Liquid nitrogen has an extremely low temperature (-196°C or -321°F), which prevents cellular activity and maintains the viability of sperm over long periods.
i) Long-Term Storage: Semen can be stored in liquid nitrogen for an extended period, potentially years, without significant loss of quality.
j) Handling Precautions: When handling stored semen, protective gear and proper hygiene are crucial to avoid contamination and maintain sperm quality.
k) Thawing: When ready for use, straws are removed from liquid nitrogen and thawed rapidly in a water bath at around 35°C (95°F).
l) Quality Control: Thawed semen is evaluated again for post-thaw motility and viability before insemination.
m) Usage: Thawed semen is loaded into an insemination gun and used for artificial insemination in cows during their fertile period.
n) Recording: Records of each batch of stored semen, including bull information and storage details, are maintained for accurate breeding management.
