Furthermore, cooling rates appear not necessarily linear, and
the lowest temperature that can be reached decreases with
increasing the distance with respect to the liquid nitrogen
level. The optimal cooling rate for cryopreserving sperm is
dependent on the type and concentration of cryoprotective
agents used in the freezing extender.
18. More rapid thawing, as attained when using higher incubation
temperatures for a shorter period, has been described to result
in higher sperm motility post-thaw. This has been attributed to
reduced recrystallization during thawing. Thawing of straws
for artificial insemination, however, is generally done at 37
C.
This can be easily done using available equipment and represents the temperature in the female reproductive tract.
Acknowledgments
Employees of the Unit for Reproductive Medicine of the University
of Veterinary Medicine Hannover (Hannover, Germany), National
Stud of Lower Saxony (Celle, Germany), and Masterrind GmbH
(Verden, Germany) are acknowledged for sharing protocols.
References
1. Curry MR (2000) Cryopreservation of semen
from domestic livestock. Rev Reprod 5:46–52
2. Samper JC, Morris CA (1998) Current methods for stallion semen cryopreservation: a survey. Theriogenology 49:895–903
3. Yeste M (2017) State-of-the-art of boar sperm
preservation in liquid and frozen state. Anim
Reprod 14:69–81
4. Barbas JP, Mascarenhas RD (2009) Cryopreservation of domestic animal sperm cells. Cell
Tissue Bank 10:49–62
5. Benson JD, Woods EJ, Walters EM, Critser JK
(2012) The cryobiology of spermatozoa. Theriogenology 78:1682–1699
6. Woelders H, Matthijs A, Zuidberg CA, Chaveiro AEN (2005) Cryopreservation of boar
semen: equilibrium freezing in the cryomicroscope and in straws. Theriogenology
63:383–395
7. Morris GJ, Faszer K, Green JE, Draper D,
Grout BW, Fonseca F (2007) Rapidly cooled
horse spermatozoa: loss of viability is due to
osmotic imbalance during thawing, not intracellular ice formation. Theriogenology
68:804–812
8. Oldenhof H, Bigalk J, Hettel C, de Oliveira
BL, Sydykov B, Bajcsy A ´ C, Sieme H, Wolkers
WF (2017) Stallion sperm cryopreservation
using various permeating agents: interplay
between concentration and cooling rate. Biopreserv Biobank 15:422–431
9. Vidament M, Ecot P, Noue P, Bourgeois C,
Magistrini M, Palmer E (2000) Centrifugation
and addition of glycerol at 22
C instead of 4
C
improve post-thaw motility and fertility of stallion
spermatozoa.
Theriogenology
54:907–919
10. Wall RJ, Foote RH (1999) Fertility of bull
sperm frozen and stored in clarified egg yolktris-glycerol extender. J Dairy Sci 82:817–821
11. Pursel VG, Johnson LA (1975) Freezing of
boar spermatozoa: fertilizing capacity with
concentrated semen and a new thawing procedure. J Anim Sci 40:99–102
12. Westendorf P, Richter L, Treu H (1975) Zur
Tiefgefrierung von Ebersperma. Labor-und
Besamungsergebnisse mit dem Hu ¨lsenberger
Pailetten-Verfahren. Dtsch Tier€ arztl Wschr
82:261–267
13. Carvajal G, Cuello C, Ruiz M, Va ´zquez JM,
Martı ´nez EA, Roca J (2004) Effects of centrifugation before freezing on boar sperm cryosurvival. J Androl 25:389–396
Cryopreservation of Sperm from Domestic Livestock
377
the lowest temperature that can be reached decreases with
increasing the distance with respect to the liquid nitrogen
level. The optimal cooling rate for cryopreserving sperm is
dependent on the type and concentration of cryoprotective
agents used in the freezing extender.
18. More rapid thawing, as attained when using higher incubation
temperatures for a shorter period, has been described to result
in higher sperm motility post-thaw. This has been attributed to
reduced recrystallization during thawing. Thawing of straws
for artificial insemination, however, is generally done at 37
C.
This can be easily done using available equipment and represents the temperature in the female reproductive tract.
Acknowledgments
Employees of the Unit for Reproductive Medicine of the University
of Veterinary Medicine Hannover (Hannover, Germany), National
Stud of Lower Saxony (Celle, Germany), and Masterrind GmbH
(Verden, Germany) are acknowledged for sharing protocols.
References
1. Curry MR (2000) Cryopreservation of semen
from domestic livestock. Rev Reprod 5:46–52
2. Samper JC, Morris CA (1998) Current methods for stallion semen cryopreservation: a survey. Theriogenology 49:895–903
3. Yeste M (2017) State-of-the-art of boar sperm
preservation in liquid and frozen state. Anim
Reprod 14:69–81
4. Barbas JP, Mascarenhas RD (2009) Cryopreservation of domestic animal sperm cells. Cell
Tissue Bank 10:49–62
5. Benson JD, Woods EJ, Walters EM, Critser JK
(2012) The cryobiology of spermatozoa. Theriogenology 78:1682–1699
6. Woelders H, Matthijs A, Zuidberg CA, Chaveiro AEN (2005) Cryopreservation of boar
semen: equilibrium freezing in the cryomicroscope and in straws. Theriogenology
63:383–395
7. Morris GJ, Faszer K, Green JE, Draper D,
Grout BW, Fonseca F (2007) Rapidly cooled
horse spermatozoa: loss of viability is due to
osmotic imbalance during thawing, not intracellular ice formation. Theriogenology
68:804–812
8. Oldenhof H, Bigalk J, Hettel C, de Oliveira
BL, Sydykov B, Bajcsy A ´ C, Sieme H, Wolkers
WF (2017) Stallion sperm cryopreservation
using various permeating agents: interplay
between concentration and cooling rate. Biopreserv Biobank 15:422–431
9. Vidament M, Ecot P, Noue P, Bourgeois C,
Magistrini M, Palmer E (2000) Centrifugation
and addition of glycerol at 22
C instead of 4
C
improve post-thaw motility and fertility of stallion
spermatozoa.
Theriogenology
54:907–919
10. Wall RJ, Foote RH (1999) Fertility of bull
sperm frozen and stored in clarified egg yolktris-glycerol extender. J Dairy Sci 82:817–821
11. Pursel VG, Johnson LA (1975) Freezing of
boar spermatozoa: fertilizing capacity with
concentrated semen and a new thawing procedure. J Anim Sci 40:99–102
12. Westendorf P, Richter L, Treu H (1975) Zur
Tiefgefrierung von Ebersperma. Labor-und
Besamungsergebnisse mit dem Hu ¨lsenberger
Pailetten-Verfahren. Dtsch Tier€ arztl Wschr
82:261–267
13. Carvajal G, Cuello C, Ruiz M, Va ´zquez JM,
Martı ´nez EA, Roca J (2004) Effects of centrifugation before freezing on boar sperm cryosurvival. J Androl 25:389–396
Cryopreservation of Sperm from Domestic Livestock
377