"This study was designed to identify a suitable freezing protocol for rabbit semen by comparing the effects of different. concentrations and equilibration times of dimethylacetamide (DMA) and dimethylsulfoxide (DMSO) on the postthaw quality of. the semen. After establishing the best protocols for each cryoprotectant, their efficacy was compared by examining the in vivo. fertilizing capacity of the semen samples. Pooled semen samples diluted in freezing medium containing 4%, 6%, or 8% DMA or. DMSO (all combined with 1% sucrose as a nonpermeating cryoprotectant) were loaded in straws and equilibrated for 5, 15, or. 45 min before freezing in liquid nitrogen vapor. The variables assessed after thawing were sperm motility, viability, osmotic. resistance, and acrosome and DNA integrity. Marked effects on these variables were shown by the cryoprotectant concentration. and equilibration time, with best results obtained using DMA 6% or DMSO, 8% and equilibration times of 45 min. These freezing. protocols were selected to compare the two cryoprotectants in an insemination trial. Three groups of 114 rabbit does (28. nulliparous and 86 multiparous in each group) were inseminated with fresh semen or with semen frozen using the optimized DMA. or DMSO protocols. Fertility rates and numbers of kids born were similar, respectively for the DMSO-frozen (79.8% and 7.7 . 0.3 young per kindling) and fresh semen (81.6% and 8.6 0.3) yet higher (P 0.05) than the rates returned using the. DMA-frozen semen (47.4% and 6.7 0.4). Moreover, the numbers of rabbits born alive when DMSO was used in the freezing. protocol, despite being lower than those recorded using fresh semen, were higher than when DMA was used as the cryoprotectant. (P 0.05). The physiological status of the does (nulliparous or multiparous) had no influence on the fertility and prolificacy. results. Our findings indicate that the cryosurvival of rabbit sperm frozen using DMSO or DMA as the cryoprotectant is highly. influenced by the concentration of cryoprotectant used and the time the semen is exposed to the agent before freezing. According. to our in vivo fertility and prolificacy data, DMSO emerged as more effective than DMA for the cryopreservation of rabbit sperm."
The cryoprotectant used, its concentration, and the equilibration time are critical for the successful cryopreservation of rabbit sperm: dimethylacetamide versus dimethylsulfoxide
IAFFALDANO, Nicolaia;DI IORIO, Michele;
2012-01-01
Abstract
"This study was designed to identify a suitable freezing protocol for rabbit semen by comparing the effects of different. concentrations and equilibration times of dimethylacetamide (DMA) and dimethylsulfoxide (DMSO) on the postthaw quality of. the semen. After establishing the best protocols for each cryoprotectant, their efficacy was compared by examining the in vivo. fertilizing capacity of the semen samples. Pooled semen samples diluted in freezing medium containing 4%, 6%, or 8% DMA or. DMSO (all combined with 1% sucrose as a nonpermeating cryoprotectant) were loaded in straws and equilibrated for 5, 15, or. 45 min before freezing in liquid nitrogen vapor. The variables assessed after thawing were sperm motility, viability, osmotic. resistance, and acrosome and DNA integrity. Marked effects on these variables were shown by the cryoprotectant concentration. and equilibration time, with best results obtained using DMA 6% or DMSO, 8% and equilibration times of 45 min. These freezing. protocols were selected to compare the two cryoprotectants in an insemination trial. Three groups of 114 rabbit does (28. nulliparous and 86 multiparous in each group) were inseminated with fresh semen or with semen frozen using the optimized DMA. or DMSO protocols. Fertility rates and numbers of kids born were similar, respectively for the DMSO-frozen (79.8% and 7.7 . 0.3 young per kindling) and fresh semen (81.6% and 8.6 0.3) yet higher (P 0.05) than the rates returned using the. DMA-frozen semen (47.4% and 6.7 0.4). Moreover, the numbers of rabbits born alive when DMSO was used in the freezing. protocol, despite being lower than those recorded using fresh semen, were higher than when DMA was used as the cryoprotectant. (P 0.05). The physiological status of the does (nulliparous or multiparous) had no influence on the fertility and prolificacy. results. Our findings indicate that the cryosurvival of rabbit sperm frozen using DMSO or DMA as the cryoprotectant is highly. influenced by the concentration of cryoprotectant used and the time the semen is exposed to the agent before freezing. According. to our in vivo fertility and prolificacy data, DMSO emerged as more effective than DMA for the cryopreservation of rabbit sperm."I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
