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Initial cooling time before freezing affects post‐thaw quality and reproductive performance of rabbit semen
Author(s) -
Di Iorio Michele,
Colonna Maria Antonietta,
Miranda Marsia,
Principe Paola,
Schiavitto Michele,
Cerolini Silvia,
Manchisi Angelo,
Iaffaldano Nicolaia
Publication year - 2018
Publication title -
animal science journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.606
H-Index - 38
eISSN - 1740-0929
pISSN - 1344-3941
DOI - 10.1111/asj.13046
Subject(s) - semen , extender , cryopreservation , sperm , semen cryopreservation , andrology , insemination , acrosome , liquid nitrogen , artificial insemination , biology , semen quality , sperm motility , zoology , chemistry , medicine , embryo , pregnancy , genetics , organic chemistry , polyurethane
The aim of this study was to investigate the effect of initial cooling time at 5°C during semen cryopreservation on post‐thaw quality and reproductive performance of rabbit semen. Pooled semen samples ( n = 6) were divided into two subsamples and cooled at 5°C for 45 or 90 min. After cooling, the semen samples were diluted to a ratio of 1:1 (v:v) with a freezing extender composed of Tris‐citrate‐glucose ( TCG ) containing 16% of dimethylsulfoxide and 0.1 mol/L sucrose. The semen was subsequently loaded in 0.25 ml straws, equilibrated at 5°C and frozen in liquid nitrogen vapor. After thawing, sperm motility, viability, osmotic resistance, acrosome and DNA integrity were assessed. Our results indicate that the longer cooling time, that is, 90 min before cryopreservation significantly improves sperm post‐thaw viability, motility and fertility. In fact, reproductive performances obtained with semen frozen after a 90 min cooling time were similar to those produced by fresh semen insemination. Hence, the present research provides an effective freezing protocol for rabbit semen that will allow for the creation of a sperm cryobank for the conservation of Italian rabbit genetic resources, as well as the use of frozen semen doses in commercial farms.