68° Congresso Nazionale SCIVAC: Le domande più frequenti in ...

68° CONGRESSO NAZIONALE SCIVAC 11-13 Marzo 2011 - Milano
LE DOMANDE PIÙ FREQUENTI IN RIPRODUZIONE CANINA E FELINA
Tutto quello che i vostri clienti osano spesso chiedere e a cui voi non sapete rispondere
14 th EVSSAR Congress - Advances in Feline Reproduction - March 11 th 2011
FROZEN DOG SEMEN
Frozen dog semen can be stored practically indefinitely, probably for 1-
2000 years or more. Dog semen can be frozen in 0.5 or 0.25 mL French straws
or in pellets. The 0.5 mL straws are in Europe preferred by most semen freezing
agencies and practitioners performing the AIs.
Extenders for freezing of dog semen
There are a number of agencies which freeze dog semen, using proprietary
extenders, such as for instance Camelot Farms, Canine Cryobank, CaniPro,
CLONE, International Canine Semen Bank and Synbiotics. Others may use
the non-proprietaty Uppsala Equex extender, and its modification the
CaniRep Uppsala-Equex II extender 8 .
Frozen semen preparation
The semen is collected and centrifuged as described above for chilled semen
preparation. It can be further processed in many different ways, using
various extenders and one or two-step dilutions (the first at room temperature
and the second after chilling and just before freezing), equilibrating it for
from 1 to 4 hours and freezing it for instance either in liquid nitrogen vapour
on a rack 4cm above the LN 2 surface in a styrofoam box or in three steps directly
into a liquid nitrogen tank 12 . Most semen banks freeze dog semen at a
final concentration of 50-100 million spermatozoa per 0.5 mL straw, and use
2-4 straws per AI. Some use a thaw medium, usually 0.5 – 1 mL for each
straw or 1-2 mL per vial of pellets. Thawing of the semen is done in a waterbath
either at 37°C for 15-60 sec or at 70°C for 8 sec. To obtain the best result
with frozen-thawed semen it is important to adhere to the thawing instructions
provided by the semen freezing agency, as the thawing method is
dependent on the freezing method.
Shipment of frozen dog semen
Frozen dog semen is shipped in liquid nitrogen containers at a temperature
of –197ºC. Semen banks today use dry-shippers, which absorb the liquid ni-
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