92 Sperm Cryopreservation in the Burmese Python (Python bivittatus) as a Model for Endangered Snakes

2018 ◽  
Vol 30 (1) ◽  
pp. 185
Author(s):  
C. Young ◽  
N. Ravida ◽  
M. Rochford ◽  
B. Durrant

The Burmese python (Python bivittatus) is listed as vulnerable by the International Union for Conservation of Nature (IUCN). Released pet Burmese pythons have detrimental effects on fauna native to southern Florida and are responsible for localised declines of several species in some parts of the Everglades National Park (IUCN, 2012; 10.2305/IUCN.UK.2012-1.RLTS.T193451A2237271.en). As part of an invasive species monitoring program, Burmese pythons were captured in the Florida Everglades and used as a model for the development of sperm cryopreservation protocols for endangered snakes. Sperm was collected by flushing the vas deferens postmortem and initial motility score (IMS; % motile × speed of progression2), plasma membrane integrity (IPL), and acrosome integrity (IAC) were recorded before cryopreservation. Sperm was extended in TEST-yolk buffer with final dimethyl sulfoxide (DMSO) or glycerol (GLY) concentrations of 8, 12, or 16%, or combinations of DMSO and GLY with final concentrations of 4:4, 6:6, or 8:8%. Sperm in 500 µL of extender was frozen in vials at 0.3°C/min to –40°C before storage in liquid nitrogen. For each treatment, triplicate vials from each of 3 males were thawed at 37°C for 90 s. Cryoprotectant was removed by centrifugation and the sperm pellet was resuspended in TCM-199+HEPES. Sperm was evaluated at 22°C immediately following resuspension (T0) and at 60 (T60) minutes. All data were expressed as a percentage of initial (%IMS, %IPL, and %IAC). The effects of freeze method on %IMS, %IPL and %IAC were analysed by ANOVA and Tukey’s HSD test. Freeze method significantly affected %IMS at T0 (P = 0.0004) and T60 (P = 0.0001), with sperm frozen in the 6%DMSO:6%GLY and 4%DMSO:4%GLY treatments resulting in the highest %IMS at both T0 (19.4% and 17.7%, respectively) and T60 (26.7% and 14.4%, respectively). Regardless of cryoprotectant concentrations, sperm frozen in a combination of DMSO and GLY exhibited significantly higher %IMS than all treatments of DMSO or GLY alone (P < 0.0001 at T0 and T60). The %IPL was significantly affected by freeze method at T0 (P < 0.0001) and T60 (P = 0.0266). Sperm frozen in 8%DMSO:8%GLY and 6%DMSO:6%GLY retained greater %IPL at both T0 (69.1% and 65.7%, respectively) and T60 (47.8% and 49.9%, respectively). Acrosome integrity was significantly affected by freeze method at T0 (P < 0.0001) and sperm frozen in 8% DMSO resulted in the greatest %IAC (56.4%). In addition, all DMSO and DMSO:GLY treatments preserved a significantly greater proportion of intact acrosomes than GLY alone (P < 0.0001). To simplify these analyses and to determine the best overall freeze method for this species, a sperm quality index (SQI) was calculated, giving equal weight to each of the 3 measured indicators of cryosurvival. The SQI analysis revealed that Burmese python sperm frozen at 0.3°C/min in either 6%DMSO:6%GLY or 4%DMSO:4%GLY exhibited significantly higher post-thaw viability at T0 and T60 than all other treatments. This study represents the first comparative, comprehensive attempt to develop a sperm cryopreservation protocol for any snake species.

2014 ◽  
Vol 26 (1) ◽  
pp. 168 ◽  
Author(s):  
C. Young ◽  
M. Curtis ◽  
N. Ravida ◽  
F. Mazotti ◽  
B. Durrant

Only 891 of the approximately 5600 lizard species have been evaluated by the International Union for Conservation of Nature (IUCN). Of those, at least one-third are threatened with extinction. However, there is no organised effort to preserve their genetic diversity through semen banking. As part of an invasive species monitoring program, Argentine black and white tegus were captured in the Florida Everglades. Following postmortem examination, sperm was collected by flushing the vas deferens and used as a model for the development of sperm cryopreservation protocols for related endangered lizards. Initial motility score (IMS; % motile × speed of progression2), plasma membrane integrity (IPL) and acrosome integrity (IAC) were recorded before freezing. Sperm was extended in TES and Tris (TEST)-yolk buffer with a final glycerol or dimethyl sulfoxide (DMSO) concentration of 8, 12, or 16%, and frozen in vials at 0.3, 1, or 6.3°C min–1. Vials were thawed at 37°C for 90 s. Cryoprotectant (CPA) was removed by centrifugation and resuspension of the sperm pellet in M199, at which time (T0) all variables were assessed and expressed as the percentage of initial (%IMS, %IPL, and %IAC). Statistical tests included multivariate ANOVA (MANOVA) and Student's t-test. Over all CPA concentrations and freeze methods, DMSO was significantly better than glycerol in maintaining %IMS (P = 0.01; 37.32 ± 3.5 and 25.44 ± 3.09, respectively) and %IAC (P < 0.01; 81.45 ± 3.45 and 22.99 ± 3.03, respectively). The 2 CPA were equally successful in protecting %IPL (P = 0.77; 56.61 ± 5.62 and 54.42 ± 4.93, respectively). The slowest freeze rate of 0.3°C min–1 was more successful than 1 and 6.3°C min–1 in preserving %IMS (P = 0.01; 37.85 ± 3.29, 26.03 ± 4.45, and 21.91 ± 4.45, respectively) and %IPL (P < 0.01; 77.43 ± 2.54, 27.99 ± 3.44, and 42.32 ± 3.44, respectively). The %IAC was not significantly affected by freeze rate (P = 0.14; 58.06 ± 6.89, 36.14 ± 9.33, and 42.99 ± 9.33, respectively). The interaction between CPA and freeze method affected %IMS (P < 0.01) and %IAC (P < 0.01), but did not affect %IPL (P = 0.28). All variables were affected (P < 0.05) by concentration of cryoprotectant as well as the interaction between freeze method and cryoprotectant concentration. To simplify these analyses and to determine the best overall freeze method for this species, a sperm quality index (SQI) was calculated, giving equal weight to each of the 3 measured indicators of cryosurvival. Table 1 depicts the product of %IMS, %IPL, and %IAC for each treatment. Because there were significant interactions between treatment parameters, each treatment was compared with all others (a–f). The SQI analysis revealed that tegu sperm frozen at 0.3°C min–1 in 8% DMSO exhibited a significantly higher post-thaw viability compared with all other treatments. Table 1.Sperm quality index (SQI) of thawed tegu sperm


2017 ◽  
Vol 29 (1) ◽  
pp. 165
Author(s):  
N. Ravida ◽  
C. Young ◽  
L. Gokool ◽  
B. S. Durrant

The desert tortoise (Gopherus agassizzii) is listed as threatened by the USA Fish and Wildlife Service and population declines continue to occur throughout most of their range. This species’ low reproductive rate, combined with the advanced age at which they reach sexual maturity, makes them vulnerable to multiple threats. Although assisted reproductive technologies can enhance breeding of many species, they are not widely used in tortoises. The objective of this study was to identify effective sperm cryopreservation protocols for the desert tortoise and possibly to other members of Testudinidae. We compared the effects of various concentrations of the cryoprotectants dimethyl sulfoxide (DMSO) and glycerol (6–20%) using 3 freezing devices at 4 freeze rates (CryoCooler, Ops Diagnostics, 2.3°C/m, 6.4°C/m; CryoMed, Thermo Scientific, 0.3°C/m or 1.0°C/m; and CoolCell, Biocision, 1.0°C/m) on several sperm parameters. Sperm was collected postmortem from the vas deferens of 9 individuals and tested either individually (n = 2), combined into 1 pool of 3 individuals, or 2 pools of 2 individuals. Sperm was extended in TEST-yolk buffer. Initial motility score (IMS; % motile × speed of progression2), plasma membrane integrity (IPL), and acrosome integrity (IAC) were recorded before cryoprotectant addition and freezing. For each treatment group, triplicate vials were thawed at 37°C for 60 s. Cryoprotectant was removed by centrifugation and the sperm pellet was resuspended in M199 + HEPES. Sperm were evaluated immediately following resuspension (T0), as well as 30 (T30) and 60 (T60) minutes postincubation at 22°C. All data were expressed as a percentage of initial (%IMS, %IPL, and %IAC). A sperm quality index (SQI) was calculated as (%IMS × %IPL × %IAC)/1,000, giving equal weight to each indicator of cryosurvival. The effects of freeze method on %IMS, %IPL, %IAC, and SQI were analysed by ANOVA and Tukey’s test. The effect of freeze method was significant at T0 and T60, with the 16% DMSO, 6.4°C/m method resulting in the highest %IMS at T0 (46.1%) and T30 (33.8%) and the 12% glyercol at 0.3°C/m highest at T60 (48.7%). Sperm frozen in 16% glycerol at 0.3°C/m had the highest %IPL at T0, T30, and T60 (91.9, 90.4, and 85.4%, respectively). Acrosome integrity was best maintained when sperm were frozen in 16% DMSO at 6.4°C/min (91.9%). The SQI was highest at T0 when sperm was frozen at 1.0°C/min in the CryoMed with highest post-thaw sperm parameters in 16% (T0) or 12% glycerol (T30 and T60). Interestingly, there were significant differences in SQI between the two 1.0°C/min freeze methods at each period, indicating that freezing device affected sperm cryosurvival, perhaps due to different freezing curves. This study indicates that mid-range (12 and 16%) cryoprotectant concentrations and slow freeze rates (0.3°C/m and 1.0°C/m) are optimal for desert tortoise sperm frozen in TEST-yolk buffer. Future studies will determine fertilizing capability of these sperm. These results may serve as a starting point for the study of sperm cryopreservation in other Testudinidae species.


2008 ◽  
Vol 20 (6) ◽  
pp. 724 ◽  
Author(s):  
Yeng Peng Zee ◽  
William V. Holt ◽  
Jaime Gosalvez ◽  
Camryn D. Allen ◽  
Vere Nicolson ◽  
...  

Swelling of koala sperm chromatin following cryopreservation has largely been attributed to the absence of intermolecular disulfide cross-linkages in the marsupial sperm nucleus. Fish spermatozoa also lack disulfide bonds within their chromatin, but have been successfully cryopreserved. The present study examined the hypothesis that the cryoprotectants used for fish sperm cryopreservation would confer a similar degree of protection on koala spermatozoa. Three concentrations each of five cryoprotectants (dimethyl sulfoxide, methanol, propylene glycol, ethylene glycol and dimethylacetamide (DMA)) were evaluated. Each treatment was compared against an established koala sperm cryopreservation protocol that uses 14% glycerol. Post-thaw assessment of progressive motility, plasma membrane integrity and mitochondrial membrane potential (MMP) revealed that protocols using 15% DMA achieved 62.2 ± 3.6% (P < 0.05) sperm survival, of which 79% (P < 0.05) had high MMP, an improvement of 32% and 40%, respectively, over sperm frozen in 14% glycerol. The percentage of spermatozoa with swollen nuclei was also lowest when frozen in 15% DMA, both immediately after thawing (18.0 ± 3.5%; P < 0.05) and after 2 h incubation at 35°C (35.8 ± 4.4%; P < 0.05). A second study was conducted to determine the optimal concentration of DMA for use in the cryopreservation of koala spermatozoa. High DMA concentrations (17.5% and 20%) resulted in significantly lower proportions of live spermatozoa showing high MMP immediately after thawing compared with spermatozoa frozen in the lower concentrations. The percentage of koala spermatozoa with swollen chromatin following cryopreservation was not affected by DMA concentration.


Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 421 ◽  
Author(s):  
Michele Di Iorio ◽  
Giusy Rusco ◽  
Roberta Iampietro ◽  
Maria Antonietta Colonna ◽  
Luisa Zaniboni ◽  
...  

The present study aimed to find an effective cryopreservation protocol for turkey semen through the combined use of dimethylsulfoxide (DMSO) and three non-permeant cryoprotectants (NP-CPAs), sucrose, trehalose, and Ficoll 70. In addition, the action of two dilution rates (1:2 and 1:4) were also investigated. Semen was processed according to two final dilution rates and the following treatments: Tselutin extender (TE)/DMSO (control), TE/DMSO + sucrose or trehalose 50, 100, 200, or 400 mM, and TE/DMSO + Ficoll 0.5, 0.75, 1, or 1.5 mM. In total 26 different combinations treatments were achieved. The diluted semen was filled up into straws and frozen on liquid nitrogen vapor. The post-thawing sperm quality was assessed by analyzing motility, membrane integrity, osmotic resistance, and DNA integrity. The results obtained revealed a significant effect of NP-CPA concentration on total and progressive motility, on most of the kinetic parameters, on membrane integrity and DNA integrity, while the post-thaw quality was less affected by dilution rate. The highest post-thaw quality for all sperm quality parameters assessed except curvilinear velocity (VCL) and DNA integrity were found in semen frozen with 1 mM Ficoll/1:4 (p < 0.05). Our findings provide an important contribution for the identification of a reference procedure for turkey semen cryopreservation, in order to create the first national avian semen cryobank.


2021 ◽  
Vol 8 ◽  
Author(s):  
Pablo García-Salinas ◽  
Victor Gallego ◽  
Juan F. Asturiano

Elasmobranchs are one of the most endangered vertebrate groups on the planet, but despite this situation the use of reproductive techniques in elasmobranch conservation strategies has been scarce. Among these techniques, sperm preservation is a potential tool for ex situ conservation and aquaria sustainability. However, there are no widespread preservation protocols for elasmobranch sperm, and shark sperm cryopreservation has never been achieved before. Here we present the establishment of successful cryopreservation protocols for elasmobranch sperm, tested in several species. We have formulated a sperm extender that can be used for different elasmobranch species, capable of maintaining sperm motility for several weeks. Additionally, we achieved the cryopreservation of sperm by previously diluting it in our extender and supplementing it with different combinations of cryoprotectants. The effects of methanol and dimethyl sulfoxide as permeating cryoprotectants were evaluated, as well egg yolk as a non-permeating cryoprotectant. Sperm quality was assessed by studying the motility and membrane integrity post-thawing, demonstrating its effectiveness in the 10 species tested, including two which are considered Critically Endangered. This is the first time that shark sperm cryopreservation has been reported, broadening our knowledge of the reproductive techniques that can be applied to elasmobranchs and laying the foundations for the first cryobanks for shark and ray sperm. Outcomes from this study will be useful for ex situ conservation efforts developed by public aquaria. A regular supply of frozen sperm will reduce the problems that result from the transport of specimens, inbreeding or lack of synchronized reproductive cycles in captivity.


Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2725
Author(s):  
Liuming Zhang ◽  
Yanhu Wang ◽  
Tariq Sohail ◽  
Yan Kang ◽  
Haoyuan Niu ◽  
...  

The present study aimed to investigate whether the presence of Tau protected Hu sheep sperm from ROS stress during storage at room temperature. The semen was diluted with extender (Tris-based) at room temperature, supplemented with different concentrations of Tau (0, 10, 20, 40, 80, or 100 mM), and stored at 15 °C. Sperm quality parameters (sperm progressive motility, kinetic parameters, plasma membrane integrity rate, acrosome integrity rate, and MMP) and antioxidant parameters (ROS, MDA, SOD, CAT, and T-AOC) were evaluated during the preservation of semen. The addition of Tau, especially at a concentration of 20 mM, exerted positive effects on sperm quality parameters and antioxidant parameters compared to the sperm without Tau treatment (control group). The addition of Tau, especially at a concentration of 100 mM, exerted negative effects on sperm quality parameters and antioxidant parameters compared to the control group. Interestingly, the results indicated that the sperm acrosome integrity rate did not change during storage time. In conclusion, the addition of Tau to sperm preserved at room temperature can enhance the antioxidant ability of sperm, reduce the LPO on the 5th day, and improve the quality of semen preserved at room temperature. These results implied that Tau had potential to enhance Hu sheep sperm reproductive performance.


2019 ◽  
Vol 31 (1) ◽  
pp. 175
Author(s):  
C. Young ◽  
N. Ravida ◽  
P. Pennington ◽  
B. Durrant

Once nearly extinct in the wild, the southern white rhinoceros is currently listed as near threatened by IUCN. This status is likely to change as poaching continues to escalate. To preserve the species’ current genetic diversity, cryopreserving and biobanking white rhinoceros sperm is imperative. The horse is the closest domestic relative of the rhinoceros and a useful model for the development of assisted reproductive technologies, including semen cryopreservation. Two equine semen cryopreservation protocols were compared to a common rhinoceros freezing method. Semen was collected from a single male on 3 occasions by electroejaculation. Initial semen parameters were 86% motility; speed 3.2 (scale 1-5); 89% plasma membrane integrity; and 95% intact acrosomes. Semen was extended 1:1 in INRA 96 (IMV Technologies, L’Aigle, France) before centrifugation at 400×g for 10min. Supernatant was removed and the sperm pellet was subjected to 1 of 2 treatments: resuspension in 500µL of either BotuCrio (Botupharma, Botucatu, Brazil) or Cryomax (ARS Inc., Chino, CA, USA), both containing a proprietary combination of glycerol and an amide as cryoprotectants. Following a 40-min cool at 4°C, extended semen was frozen in vials at a cooling rate of 30°C/min for 3min before LN submersion. Control semen was extended 1:1 in TEST-Y buffer without cryoprotectant and cooled for 2.5h before adding glycerol to a final concentration of 4%. Extended sperm (500µL) was frozen in vials at 12.5°C/min for 15min before LN submersion. Initial motility score (IMS;% motile×speed of progression2), plasma membrane integrity (IPL), and acrosome integrity (IAC) were recorded after extension. All vials were thawed at 37°C for 60s and the cryoprotectant was removed by centrifugation. Sperm pellets were resupended in M199+HEPES and sperm was evaluated for the characteristics described above at 37°C at 0, 30, and 60min (T0, T30, T60) post-thaw. All data are expressed as a percentage of initial (%IMS,%IPL, and%IAC) to account for the differences in sperm parameters between ejaculates. Cryopreservation protocol significantly affected%IMS at T0 (P=0.0131, Table 1). Although the differences were significant only at T0, sperm frozen in Botucrio or Cryomax tended to maintain a higher%IMS than the control freeze at all time points. However, sperm frozen in Cryomax lost a greater percentage of%IMS over time (67% from T0 to T60v. 44 and 46% for Botucrio and TEST-Y, respectively). Cryopreservation protocol did not affect%IAC or%IPL at any time point, but again Cryomax and Botucrio tended to be higher than TEST-Y. This study indicates that rhinoceros sperm may suffer less cryodamage in Botucrio or Cryomax frozen at 30°C/min than in the conventional TEST-Y frozen at 12.5°C/min. Table 1.Percent of initial motility score (IMS), plasma membrane integrity (IPL), and acrosome integrity (IAC) at 0, 30, and 60min post-thaw (T0, T30, and T60, respectively)


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 591 ◽  
Author(s):  
Zhendong Zhu ◽  
Rongnan Li ◽  
Chengwen Feng ◽  
Ruifang Liu ◽  
Yi Zheng ◽  
...  

It takes several hours for mammalian sperm to migrate from the ejaculation or insemination site to the fertilization site in the female reproductive tract in which glucose, amino acids, and fatty acids are regarded as the primary substrates for ATP generation. The present study was designed to investigate whether oleic acid and palmitic acid were beneficial to boar sperm in vitro; and if yes, to elucidate the mechanism that regulates sperm motility. Therefore, the levels of oleic acid and palmitic acid, motility, membrane integrity, acrosome integrity, and apoptosis of sperm were evaluated. Moreover, the enzymes involved in mitochondrial β-oxidation (CPT1: carnitine palmitoyltransferase 1; ACADVL: long-chain acyl-coenzyme A dehydrogenase) were detected with immunofluorescence and Western blotting. Consequently, the ATP content and the activities of CPT1, ACADVL, malate dehydrogenase (MDH), and succinate dehydrogenase (SDH) were also measured. We observed that CPT1 and ACADVL were expressed in boar sperm and localized in the midpiece. The levels of oleic acid and palmitic acid were decreased during storage at 17 °C. The addition of oleic acid and palmitic acid significantly increased sperm motility, progressive motility, straight-line velocity (VSL), membrane integrity, and acrosome integrity with a simultaneous decrease in sperm apoptosis after seven days during storage. When sperm were incubated with oleic acid and palmitic acid at 37 °C for 3 h, the activities of CPT1 and ACADVL, the ATP level, the mitochondrial membrane potential, the activities of MDH and SDH, as well as sperm motility patterns were significantly increased compared to the control (p < 0.05). Moreover, the addition of etomoxir to the diluted medium in the presence of either oleic acid or palmitic acid and the positive effects of oleic acid and palmitic acid were counteracted. Together, these data suggest that boar sperm might utilize oleic acid and palmitic acid as energy substrates for ATP production via β-oxidation. The addition of these acids could improve sperm quality.


2020 ◽  
Vol 7 ◽  
Author(s):  
J. Suwimonteerabutr ◽  
S. Chumsri ◽  
P. Tummaruk ◽  
Morakot Nuntapaitoon

The objective of the present study was to determine the effect of butaphosphan and cyanocobalamin supplementation in semen extender on chilled boar sperm quality and life span. A total of 35 ejaculates of boar semen were included. The semen was diluted with Beltsville thawing solution extender supplemented with different concentrations of butaphosphan and cyanocobalamin [0 (control), 0.1, 0.2, 0.3, 0.4, and 0.5%] in the diluted semen. The semen samples were evaluated using a computer-assisted sperm analysis system to determine sperm motility and sperm kinetic parameters (i.e., the curvilinear velocity, VCL; straight line velocity, VSL; average path velocity, VAP; linearity, LIN; straightness, STR; amplitude of lateral head, ALH; wobble, WOB; and beat cross frequency, BCF). Additionally, sperm viability, acrosome integrity, mitochondrial activity, and plasma membrane integrity were evaluated after 4 (day 0), 72 (day 3), 120 (day 5), and 168 (day 7) h of storage using SYBR-14–ethidium homodimer-1 (EthD-1), EthD-1, JC-1, and the short hypo-osmotic swelling test, respectively. The analyses were carried out by using the general linear mixed model (MIXED) procedure of SAS. The statistical models for each data set included group, day after storage, and interaction between group and day after storage. The boar was included as a random effect. On day 0 after storage, progressive motility, VCL, VSL, VAP, and plasma membrane integrity of boar sperm in 0.3% of butaphosphan and cyanocobalamin supplementation were greater than those in the 0.4 and 0.5% groups (P &lt; 0.05). On day 3 after storage, total motility and progressive motility, VCL, VSL, VAP, LIN, WOB, BCF, and plasma membrane integrity in 0.3% of butaphosphan and cyanocobalamin supplementation were significantly greater than those in the control group (P &lt; 0.05). The total motility and progressive motility, VAP, and WOB in 0.3% of butaphosphan and cyanocobalamin supplementation were greater than those in the control group on day 5 after storage (P &lt; 0.05). No effects of butaphosphan and cyanocobalamin supplementation on acrosome integrity and mitochondria activity were found on days 3, 5, and 7 after storage. However, the motility and progressive motility and the values for all sperm kinetic parameters except ALH in 0.3% of butaphosphan and cyanocobalamin supplementation were greater than those in the control group on day 7 after storage (P &lt; 0.05). In conclusion, 0.3% of butaphosphan and cyanocobalamin supplementation in semen extender improved sperm motility, sperm activity, morphology, and life span in chilled boar sperm.


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 691
Author(s):  
Beatriz Cardoso ◽  
Irene Sánchez-Ajofrín ◽  
Cristina Castaño ◽  
Olga García-Álvarez ◽  
Milagros Cristina Esteso ◽  
...  

Sperm cryopreservation is a complex process that needs to be adapted to wild and domestic avian species to ensure proper efficiency. Because of its accessibility, the peregrine falcon may be used as a good model for studying other raptor species. To find the most optimal cryopreservation protocol for peregrine falcon ejaculates, sperm parameters such as motility, viability, DNA fragmentation, acrosome integrity, and mitochondrial activity were analyzed under different conditions by varying the freezing method (slow freezing in straws vs. ultrarapid freezing in pellets), thawing conditions (37 °C for 30 s vs. 5 °C for 1 min), type of cryoprotectant (DMA vs. DMSO), and concentration of DMSO (4% vs. 8%). Results show that slow cryopreservation in straws yielded greater percentages (p < 0.05) of motile spermatozoa (22.5% ± 4.4% vs. 0.0% ± 4.1%), viable spermatozoa with intact acrosomes (84.6% ± 4.3% vs. 77.4% ± 4.3%), and spermatozoa with active mitochondria (41.0% ± 6.7% vs.12.8% ± 6.7%), compared with those obtained by the ultrarapid freezing in pellets. However, no differences were found between different thawing conditions. Moreover, all sperm motility parameters were greater (p < 0.05) when DMSO was used during freezing compared with DMA, although the use of 3% and 8% DMSO produced similar results. In conclusion, these results represent important progress in the study of falcon semen cryopreservation protocol, highlighting the crucial steps of the process and the most suitable conditions.


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