Issue |
Reprod. Nutr. Dev.
Volume 42, Number 6, November-December 2002
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Page(s) | 583 - 586 | |
DOI | https://doi.org/10.1051/rnd:2002044 |
DOI: 10.1051/rnd:2002044
Successful pregnancies in cows following double freezing of a large volume of semen
Amir Arav, Yoel Zeron, Haim Shturman and Haim GacituaInstitute of Animal Science, Agricultural Research Organization (ARO), The Volcani Center, Bet Dagan, 50250, Israel
Abstract
The objective of the following paper is to describe a new technology for large volume
and double freezing of semen in 12 mL test tubes. Semen from two different bulls was
frozen with a new technique using 12 mL test tubes and was refrozen after thawing in
mini straws. All freezing was done in a "Multi thermal gradient" (MTG) freezing apparatus,
which moves the container at a constant velocity (V) through a thermal gradient (G)
producing a controlled cooling rate B = (G)
(V). Each of the two bulls ejaculated
were evaluated for post thaw motility in the lab and then in a field trial which was
carried out in a split sample mode. We inseminated 105 cows after a double
freezing/thawing cycle, and another 123 cows were inseminated with semen frozen
in mini-straws and a conventional method. The results showed a 75
5% post thaw
motility after freezing a 12 mL test tube and 50
5% after a second freezing/thawing
in mini-straws, respectively. Controlled vapour freezing showed a 60
10% post
thaw motility. The results of the field trial showed a pregnancy rate of 44%
(47/105) for the double freezing group in comparison to 45.5% (56/123) for the
controlled group. These results can be beneficial for large volume freezing,
and therefore for bull semen cryobanking in a large volume which will be followed
by second freezing in a regular insemination volume.
Key words: freezing / cryopreservation / cryobanking / sperm / bull
Correspondence and reprints: Amir Arav
e-mail: arav@agri.huji.ac.il
© INRA, EDP Sciences 2002