129 IMPROVEMENT OF BOAR SPERM CRYOSURVIVAL BY THE OPTIMIZATION OF CRYOPRESERVATION CONDITIONS

2007 ◽  
Vol 19 (1) ◽  
pp. 182
Author(s):  
J. Roca ◽  
M. Hernandez ◽  
T. Cremades ◽  
J. M. Vazquez ◽  
E. A. Martinez

One of the most important limiting factors for the efficient commercial application of frozen–thawed semen on pig artificial insemination programs is the significant and consistent inter-boar variability in sperm cryosurvival. The objective of the present study was to evaluate the effectiveness of different cryopreservation conditions (CCs) for freezing and thawing boar spermatozoa, and to determine their suitability for individual boars, with particular reference to those that showed an intrinsic poor sperm cryosurvival. Using a split-ejaculate technique, single ejaculates from 53 boars were suspended in lactose-egg yolk extender containing 2 or 3% final glycerol concentration, packaged in 0.5-mL straws, cooled at rates of 10, 40, or 60�C min-1 using a programmable cell freezer, and stored in liquid nitrogen; the frozen samples were warmed at ≈1200�C min-1 (37�C water bath for 20 s) or ≈1800�C min-1 (70�C for 8 s). The cryopreservation condition including 2% glycerol, 40�C min-1 of cooling, and ≈1200�C min-1 of warming was considered as the control. Frozen–thawed sperm were evaluated at 30 and 150 min post-thawing for sperm motility (CASA system), plasma membrane integrity (SYBR-14 and propidium iodide), and acrosome membrane integrity (FITC-peanut agglutinin and propidium iodide). Data were analyzed using 2 different ANOVA mixed models. Whereas cooling rate had no influence (P ≥ 0.05), glycerol concentration and warming rate, both independently, affected (P ≤ 0.05) all post-thawing sperm assessments. No interaction (P ≥ 0.05) among effects was detected for any of the sperm parameters assessed. Evaluating the combined effect of glycerol concentration and warming rate, the highest post-thaw sperm quality was achieved from the semen samples frozen with 3% of glycerol and thawed at ≈1800�C min-1. Significant differences (P ≤ 0.05) among ejaculates (boars) to support the different CCs were shown in all post-thaw sperm assessments. Three different (P ≤ 0.05) ejaculate (boar) populations, defined by PATN analysis (PATN software package, CSIRO, Canberra, Australia), were identified according to post-thaw sperm assessments in semen samples frozen and thawed using control CC (populations so-called 'good', 'moderate', and 'bad' sperm freezers). Different (P ≤ 0.05) susceptibility in the tolerance of spermatozoa to support the different CCs was found among the ejaculate populations. Whereas spermatozoa from ejaculates considered as 'good' freezers are relatively unaffected (P ≥ 0.05), those from 'moderate' and, mainly, 'bad' freezers are very sensitive (P ≤ 0.05) to the modifications in the CCs. In conclusion, slight modifications in the CCs — glycerol concentration and warming rate for thawing — can improve the sperm cryosurvival of some ejaculates (boars), the improvement being particularly larger in those ejaculates (boars) classified as ' bad' sperm freezers. This work was supported by CICYT (AGF2005-00760), Madrid, Spain.

2007 ◽  
Vol 19 (1) ◽  
pp. 182 ◽  
Author(s):  
L. Rodriguez-Vilar ◽  
M. Hernandez ◽  
C. Lopez-Sanchez ◽  
J. M. Vazquez ◽  
E. A. Martinez ◽  
...  

Butylated hydroxytoluene (BHT) has proven to be efficient as a supplement for cryopreservation boar spermatozoa (Roca et al. 2004 J. Androl. 25, 397–405). Moreover, it has been successfully used as an egg yolk substitute to cryopreserve goat spermatozoa (Khalifa and El-Saidy 2006 Anim. Reprod. Sci. 93, 303–315). The objective of this study was to evaluate the effectiveness of BHT as an egg yolk substitute for freezing boar spermatozoa. Nine sperm-rich ejaculate fractions were collected from 3 boars (3 ejaculates per boar) using the gloved-hand method. After centrifugation (2400g for 3 min), the sperm pellet of each ejaculate was split into 5 aliquots. The aliquots were diluted (to a final concentration of 1 � 109 sperm/mL) in a Tris-citric-glucose extender with 3% glycerol and supplemented with 20% egg yolk (positive control, PC aliquot) or BHT at the final concentrations of 0 (negative control, NC aliquot), 0.2, 0.4, and 0.8 mM. Diluted semen samples were dispensed into 0.5-mL straws, and frozen in a programmable cell freezer at 20�C min. Thawing was carried out in a water bath at 70�C for 8 s. Post-thaw sperm survival was assessed according to total sperm motility (TSM, %) using a CASA system (SCA�; Microptic, Barcelona, Spain), and plasma membrane integrity (PMI, %) and acrosome membrane integrity (AMI, %) using a flow cytometric procedure (SYBR-14/propidioum iodide/FITC-phycoerythrin), at 30 and 150 min post-thawing in diluted Beltsville thawing solution with spermatozoa held in a waterbath at 37�C (3 straws per ejaculate). Data were analyzed using a ANOVA mixed model including the main effects of aliquot, boar, post-thaw assessment time, and their interactions, with ejaculate and straw as random effects. All main effects had significant influence (P ≤ 0.01) in all post-thaw sperm assessments. However, no interactions (P ≥ 0.05) among main effects were shown. Data were combined for the 2 post-thaw assessment times. The best (P ≤ 0.05) post-thaw sperm quality (mean � SEM) was achieved in PC aliquots (47.11 � 3.10, 58.98 � 2.78, and 51.35 � 3.42 for TSM, PMI, and AMI, respectively). In NC aliquots, the percentage of TSM, PMI, and AMI were always below 1% (P ≤ 0.05). BHT has a beneficial (P ≤ 0.05) effect on post-thaw sperm assessments, and no differences (P ≥ 0.05) among concentrations were shown. The mean post-thaw sperm quality in the BHT aliquots was 8.50 � 0.80, 20.29 � 0.53, and 16.03 � 0.55 for TSM, PMI, and AMI, respectively. On the basis of these data, we can conclude that BHT has a protective effect for boar spermatozoa during the cryopreservation process. However, BHT alone is insufficient to replace the protective effect of egg yolk. This work was supported by CICYT (AGF2005-00706), Madrid, Spain.


2006 ◽  
Vol 18 (2) ◽  
pp. 164
Author(s):  
M. Thys ◽  
A. Van Soom ◽  
J. Dewulf ◽  
T. Rijsselaere ◽  
A. de Kruif

The substantial decrease of sperm quality after cryopreservation remains an important issue in the artificial insemination industry. Sperm coating with Triladyl® (Minitübe, Tiefenbach, Germany) during ejaculation can preserve sperm characteristics and oocyte penetrating capacity of fresh bovine spermatozoa stored in egg yolk diluent for up to 6 days (De Pauw et al. 2003 Theriogenology 59, 1109–1122). Since collecting semen in a tube containing egg yolk-Tris extender (sperm coating) limits the period of contact between spermatozoa and seminal plasma, the present experiment was conducted to assess if this slightly adjusted method of sperm collection could also have a significant effect on bovine sperm quality after cryopreservation. Semen of five young Holstein Friesian bulls was collected by means of an artificial vagina connected to an empty tube (Group 1; five ejaculates per bull) or a tube containing 4 mL of an egg yolk-Tris extender (Groups 2 and 3; each five ejaculates per bull). The semen samples of Group 1 were conventionally diluted in straws (60 × 106 sperm/mL), frozen, and stored in liquid nitrogen. The samples of Group 3 were centrifuged, and after removing diluent and seminal plasma, the sperm pellet was conventionally diluted and processed. The samples of Group 2 were processed without removal of the supernatant. After thawing each ejaculate was analyzed for average path velocity (VAP), beat cross frequency (BCF), and progressive motility (PROG) using CASA (Minitübe, Tiefenbach, Germany). Furthermore, the membrane integrity of each sample was evaluated using fluorescent SYBR®–14/PI staining (BD Biosciences, Erembodegem, Belgium). All parameters were compared among the three groups of sperm using univariate analysis of variance (SPSS 12.0; SPSS, Inc., Chicago, IL, USA). No significant differences could be observed among the three groups for all of the evaluated sperm characteristics (Table 1). A significant effect of the bull could be determined for all analyzed parameters (P ≤ 0.02), except for the percentage of moribund cells. Nevertheless, the group-bull interaction was never statistically significant. Coating bovine sperm with an egg yolk-Tris extender during ejaculation cannot prevent the substantial deterioration of the spermatozoa that occurs during freezing and thawing since this method of sperm collection does not significantly influence the motility parameters or the membrane integrity after thawing. Table 1. VAP, BCF, PROG, and percentage of membrane-intact, dead, and moribund spermatozoa for the three groups of sperm This research was supported by IWT (no. IWT/020727).


2019 ◽  
Vol 67 (1) ◽  
pp. 106-114
Author(s):  
Zhao Namula ◽  
Fuminori Tanihara ◽  
Manita Wittayarat ◽  
Maki Hirata ◽  
Nhien Thi Nguyen ◽  
...  

Tris (hydroxymethyl) aminomethane (Tris) has been used as a pH regulator for buffering the pH of dilution extenders for boar semen, such as the Modena extender. The purpose of the present study was to assess the effects of Tris supplementation at different concentrations (0, 8, 24 and 72 μM) into the freezing extender on the quality and fertilising capacity of frozen-thawed boar spermatozoa. The results showed that the supplementation of 24 μM of Tris gave significantly higher percentages of sperm viability and plasma membrane integrity than those of the control group at any time point of assessment (0 h and 3 h post-thawing) (P < 0.05). However, there were no significant differences in the acrosome integrity parameter among the groups. Higher percentages of sperm motility were observed in the spermatozoa cryopreserved with 24 μM of Tris compared to the control groups when the samples were analysed 0 h after thawing (P < 0.05). However, an increase of the Tris concentration to 72 μM did not enhance the sperm motility parameters. The total numbers of fertilised oocytes and blastocysts obtained with spermatozoa frozen with 24 μM Tris were significantly higher than those of the control group without Tris (P < 0.05). In conclusion, the supplementation of 24 μM Tris into the freezing extender contributes to a better boar sperm quality and fertilising capacity after the process of freezing and thawing.


2021 ◽  
Vol 63 (1) ◽  
Author(s):  
Maja Zakošek Pipan ◽  
Petra Zrimšek ◽  
Breda Jakovac Strajn ◽  
Katarina Pavšič Vrtač ◽  
Tanja Knific ◽  
...  

ABSTRACT Background Wide variation in fertility rates is observed when using frozen bull semen, even when the bulls have met quality standards for semen production. Therefore, a simple and reliable test to assess the freezing potential of bull semen based on the analysis of fresh semen or blood would be of great value. Attention is now turning to assessment of seminal plasma components such as proteins and elements. In the present study, the concentrations of macro- and microelements in fresh bull semen plasma and in serum and their correlation with quality characteristics of fresh semen and with semen quality after freezing and thawing were determined. Ejaculates were collected from 30 mature bulls, and semen volume, concentration, sperm motility, morphology, tail membrane integrity, plasma membrane permeability and DNA fragmentation were determined on the day of collection and after freezing and thawing. The concentrations of macroelements (Na, Mg, K and Ca) and microelements (Cu, Fe, Zn and Se) were determined in the seminal plasma and serum. The semen samples were classified into satisfactory and unsatisfactory groups according to the fresh semen quality. Results Zinc and Se levels measured in serum were associated with almost all fresh and frozen-thawed semen quality characteristics, while Fe levels were associated only with acrosomal defects in fresh semen. Zinc and Fe levels in fresh seminal plasma were associated with various quality characteristics of fresh and frozen-thawed semen, while Se level in fresh seminal plasma was not associated with any of the semen quality characteristics. Conclusions Microelements were shown to be useful as biomarkers involved in the analysis of bull sperm quality and could be used as an additional tool to predict bull semen quality after freezing and thawing. Our results confirm that the analysis of Zn and Se levels in serum and Zn, Cu and Fe levels in fresh seminal plasma can provide information to discriminate between bull semen samples with spermatozoa with high or low cryotolerance.


Zygote ◽  
2018 ◽  
Vol 26 (4) ◽  
pp. 301-307 ◽  
Author(s):  
José A. B. Bezerra ◽  
Andréia M. Silva ◽  
Patrícia C Sousa ◽  
Lívia B. Campos ◽  
Érica C. G. Praxedes ◽  
...  

SummaryThe aim of this study was to establish a functional freezing–thawing protocol for epididymal sperm of collared peccaries (Pecari tajacu L., 1758) by comparing different extenders. The epididymal sperm from 12 sexually mature males was recovered by retrograde flushing using Tris-based or coconut water-based (ACP®-116c) extenders. After initial evaluation, samples were diluted and frozen with the same extenders to which 20% egg yolk and 6% glycerol were added. After 2 weeks, thawing was performed at 37°C/60 s and sperm motility, vigour, morphology, functional membrane integrity, sperm viability, sperm plasma membrane integrity, and a computer-assisted semen analysis (CASA) were assessed. In addition, to evaluate the survival of frozen–thawed sperm, a thermal resistance test (TRT) was executed. Samples preserved using Tris were in better condition compared with those preserved using ACP®, showing higher values for most assessments performed, including CASA and the TRT (P<0.05). After determining Tris to be the better of the two extenders, additional samples were thawed using different thawing rates (37°C/60 s, 55°C/7 s, 70°C/8 s). Sperm thawed at 37°C/60 s had the greatest preservation (P<0.05) of viability (54.1 ± 5.9%) and functional membrane integrity (43.2 ± 5.4%), and had higher values for various CASA parameters. In conclusion, we suggest the use of a Tris-based extender added to egg yolk and glycerol for the cryopreservation of epididymal sperm obtained from collared peccaries. In order to achieve better post-thawing sperm quality, we suggest that samples should be thawed at 37°C/60 s.


2009 ◽  
Vol 21 (1) ◽  
pp. 138
Author(s):  
J. E. Rodríguez-Gil ◽  
M. Hernández ◽  
M. M. Rivera ◽  
L. Ramió-Lluch ◽  
J. Ballester ◽  
...  

The optimization of freezing extenders is an essential issue for enhancing boar sperm cryosurvival. The aim of the present study was to disclose the role of glucose concentration of freezing extender on the metabolic activity of frozen–thawed spermatozoa. To achieve it, pooled sperm-rich ejaculate fractions from 5 mature and fertile boars (3 ejaculates per boar) were collected using the gloved-hand method. After centrifugation (2400g for 3 min), the sperm pellet was split into 7 aliquots. The aliquots were diluted to a final concentration of 1 × 109 sperm mL–1, in a Tris-citric extender supplemented with 20% egg-yolk, 3% glycerol, and 0, 0.05, 2, 4, 10, 55, or 185 mm glucose. All the extenders were adjusted to a pH of 6.8 and 310 mOsm kg–1 to avoid osmolarity effects. Extended semen samples were dispensed into 0.5-mL straws, and frozen in a programmable cell freezer at 20°C min–1. Thawing was carried out in a water bath at 37°C for 20 s. Afterward, an analysis of protein phosphorylation in tyrosine residues was carried out through bi-dimensional electrophoresis followed by a Western blot analysis. This analysis indicated that sperm samples frozen in extenders without glucose showed specific changes in the tyrosine phosphorylation pattern compared with fresh sperm. Furthermore, the addition of glucose in increasing concentrations to the freezing extender was accompanied by a concentration-dependent decrease in the overall tyrosine phosphorylation pattern, especially in proteins with a molecular weight ranging from 150 to 200 kDa and an acidic isoelectric point (pI). The maximal decrease was observed in spermatozoa frozen in the extender containing 185 mm glucose, in which an additional decrease in the tyrosine phosphorylation of proteins ranging from 60 to 80 kDa, and a basic pI was also observed. These results suggest that glucose is a modulator in the resistance of boar sperm to support freezing and thawing process, because the precise protein phosphorylation pattern of spermatozoa is directly linked to their functional status. In this way, a precise control of the glucose concentration of the freezing extender would be required to improve boar sperm cryoresistance. Supported by CICYT (AGL2005-00760 and AGL2004-04756-C02-02/GAN), Madrid and GERM (04543/07), Murcia, Spain.


2020 ◽  
Vol 65 (No. 4) ◽  
pp. 115-123
Author(s):  
Marija Jovičić ◽  
Eva Chmelíková ◽  
Markéta Sedmíková

Sperm cryopreservation is the best technology for long-term storage of the semen. However, the damage of boar spermatozoa by cryopreservation is more severe than in other animal species and a standardized freezing protocol for efficient cryopreservation has not been established yet. Semen quality and freezability vary greatly between breeds as well as between individual boars and even the season. Boar spermatozoa are sensitive to low temperatures; they sustain damage and a high rate of mortality and freezing/thawing the boar semen may strongly impair the sperm function and decrease the semen quality. The freezability of boar semen can be influenced by a cryopreservation procedure, and also by using various additives to freezing and thawing extenders such as antioxidants. In order to obtain acceptable results after thawing the boar semen, it is necessary to combine an optimal amount of additives (glycerol, egg yolk, sugars, antioxidants), cooling and warming velocities.


1972 ◽  
Vol 52 (1) ◽  
pp. 65-72 ◽  
Author(s):  
L. M. SANFORD ◽  
G. J. KING ◽  
J. W. MACPHERSON

Boar and bull spermatozoa were diluted in a skim milk–egg yolk–glucose extender containing 0, 7.5, or 15% glycerol (v/v) and incubated aerobically for 6 hr at 37 C. Other partially diluted boar semen samples were cooled to 5 C. Glycerol was added to a final concentration of 0, 7.5, and 15%. Samples were frozen to −79 C, rewarmed, and incubated for 3 hr at 37 C. The presence of glycerol in the extender depressed (P < 0.01) the oxygen uptake by nonfrozen boar and bull spermatozoa during the 6-hr incubation period. The reduction of oxygen uptake by semen samples increased as the level of glycerol in the extender increased. There was a corresponding decrease (P < 0.01) in the number of motile cells at the conclusion of the incubation period. Glycerol appeared to have more of a detrimental effect on boar spermatozoan oxygen uptake. The rate of oxygen uptake by boar semen samples postfreezing was extremely depressed, suggesting that spermatozoa surviving the freezing process metabolize at a much lower rate than normal. Active progressive motility of most of the surviving boar spermatozoa ceased within 1–2 hr of incubation under the in vitro conditions of this experiment.


2016 ◽  
Vol 12 (2) ◽  
pp. 21-28
Author(s):  
Monika Trzcińska ◽  
Magdalena Baryła

The objective of the study was to determine the effect of butylated hydroxytoluene (BHT) on the quality and fertilizing capacity of frozen-thawed (FT) boar semen. Semen from five boars (36 ejaculates) was resuspended in lactose-egg yolk-glycerol extender supplemented with 0 (control), 1.0 (R1), 1.5 (R2) or 2.0 mM BHT (R3). Sperm quality was assessed based on motility (CASA; TM: total motility; PM: progressive motility), phosphatidylserine (PS) translocation across the plasma membrane (Annexin-V-FLuos Staining Kit) and DNA fragmentation (TUNEL Assay). The FT semen was also used for intrauterine artificial insemination (AI) of synchronized gilts. The fertilizing capacity of the FT semen was assessed on the basis of the gilt insemination rate and the number of morphologically normal embryos. The quality of the preimplantation embryos was determined by observing a TUNEL-positive reaction. The highest percentage of progressive motile and viable spermatozoa was noted in extender R3 (74.8 ±4.4% and 63.7 ±5.8%), as compared with the control (38.3 ±2.8% and 36.1 ±2.6%). The addition of BHT to the extender did not increase early apoptotic changes in the frozen-thawed spermatozoa with respect to the control. Irrespective of the variant of the extender, cryopreservation and thawing did not induce fragmentation in the boar spermatozoa. The highest number of morphologically normal embryos from inseminated gilts was observed in the case of semen cryopreserved in extender supplemented with 1.5 mM BHT. No significant differences were observed in DNA fragmentation in the expanded blastocysts from gilts inseminated with FT semen cryopreserved in the extenders analysed.


Author(s):  
P. J. Chaudhary ◽  
A. J. Dhami ◽  
D. V. Chaudhari ◽  
K. K. Hadiya ◽  
J. A. Patel

This study was undertaken on three mature bulls each of Gir cattle and Surti buffalo breeds to evaluate the comparative efficacy of egg yolk based standard TFYG (Tris-citrate-fructose-yolk-glycerol) extender and egg yolk free soybean based commercial extenders Optixcell® (IMV, France) and Andromed® (Minitube, Germany) under split-sample technique. The ejaculates (9/bull) were extended @ 100×106 sperm ml-1 with three extenders and frozen using biofreezer following 4 hr of equilibration. The pooled means of progressively motile sperm observed (irrespective of extenders) at initial, pre-freeze and post-thaw stage in Gir bulls semen were 76.53±0.53, 71.11±0.53 and 39.86±0.90% and in Surti buffalo 80.76±0.39, 74.65±0.45 and 40.35±1.07%, respectively. The corresponding values for live sperm were 75.64±0.76, 69.01±0.97 and 47.99±1.11 % for Gir and 80.90±0.45, 75.76±0.48 and 52.33±0.86 % for Surti buffalo; and those of intact acrosome 94.29±0.25, 90.29±0.27 and 79.29±0.33 % for Gir bulls, and 93.94±0.21, 89.94±0.23 and 78.95±0.26 % for Surti buffalo semen, respectively. The HOS reactive sperm at initial, pre-freeze and post-thaw stage were 76.18±0.74, 71.04±0.76 and 27.90±0.70 % for Gir, and 81.83±0.35, 76.47±0.39 and 27.83±0.68 % for Surti bulls, respectively. The overall mean post-thaw incubation (37°C) survival of spermatozoa observed at 60, 120 and 180 min were 28.40±0.91, 17.78±0.86 and 9.44±0.72% for Gir bulls semen, and 28.01±0.99, 18.40±1.01 and 10.51±0.93% for Surti buffalo semen, respectively. Optixcell was proved superior, and at par with TFYG, than the Andromed in maintaining greater motility, viability, morphology, acrosomal/plasma membrane integrity including post-thaw sperm longevity of cattle and buffalo spermatozoa with significant differences only in sperm motility and post-thaw longevity. The motile, live and HOST reactive sperm were significantly higher in buffalo semen than cattle at initial and pre-freeze stage, but not at post-thaw stage. The results showed that egg yolk free commercial Optixcell extender and egg yolk based TFYG extender were at par in terms of most of the sperm quality traits, hence any one of them can be preferred over Andromed for successful routine cryopreservation of cattle and buffalo semen.


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