• Animal Bioscience
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• v.35 no.11
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• pp.1666-1674
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• 2022

Objective: Letrozole, a potent aromatase inhibitor, is known to have the potential to modify male reproductive function by altering sex hormone levels. This study aimed to evaluate the semen and testicular characteristics and hormonal profile of aged Mrakhoz bucks (Capra hircus) treated with letrozole. Methods: Twelve Markhoz male goats, aged between 4.5 to 5.5 years with an average body weight (BW) of 61.05±4.97 kg were used for the study. Animals were randomly divided into two equal groups and subcutaneously received either 0.25 mg/kg BW of letrozole or a control every week for 2 months. The semen collections were performed every 10 days, and blood samples and testicular biometric records were collected at 20 days intervals. Results: Letrozole causes increased testosterone and follicle-stimulating hormone levels, testosterone to estradiol ratio, semen index and reaction time during the period from 20th to 60th days (p<0.05). Furthermore, letrozole-treated bucks had higher semen volume, sperm concentration, and total sperm per ejaculate from 30th to 60th days (p<0.05). However, no differences occurred between the groups in scrotal circumference, relative testicular volume, semen pH, abnormality, acrosome integrity, and membrane integrity of sperm during the study (p>0.05). The serum luteinizing hormone levels, sperm viability, motility, and progressive motility increased, and estradiol levels decreased after 40th to 60th days of letrozole treatment (p<0.05). Conclusion: Letrozole application to aged Markhoz bucks provokes reproductive hormonal axis which, in turn, induces enhancement of semen production and quality.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.1
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• pp.20-27
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• 2024

Objective: While sperm freezing (cryopreservation) is an effective method for preserving fertility, it can potentially harm the structure and function of sperm due to an increase in the production of reactive oxygen species. This study aimed to assess the impact of zinc oxide nanoparticles (ZnONPs) and selenium oxide nanoparticles (SeONPs) on various sperm functional parameters, including motility, plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), acrosome membrane integrity (ACi), and malondialdehyde (MDA) levels. Methods: Semen samples were collected from 20 Albino Wistar rats. These samples were then divided into six groups: fresh, cryopreservation control, and groups supplemented with SeONPs (1, 2, 5 ㎍/mL) and ZnONPs (0.1, 1, 10 ㎍/mL). Results: Statistical analysis revealed that all concentrations of SeONPs increased total motility and progressive reduction of MDA levels compared to the cryopreservation control group (p<0.05). However, supplementation with ZnONPs did not affect these parameters (p>0.05). Conversely, supplements of 1 and 2 ㎍/mL SeONPs and 1 ㎍/mL ZnONPs contributed to the improvement of PMI and ACi (p<0.05). Yet, no significant change was observed in MMP with any concentration of SeONPs and ZnONPs compared to the cryopreservation control group (p>0.05). Conclusion: The findings suggest that optimal concentrations of SeONPs may enhance sperm parameters during the freezing process.

• Journal of Embryo Transfer
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• v.33 no.4
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• pp.321-326
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• 2018

In this study, two epididymal spermatozoa recovery methods in relation to sperm number, motility, viability and acrosome reaction were examined. Seven bulls were castrated and 7 testicles with epididymides were transferred to the laboratoy. Epididymis in each bull was randomly used for flushing and mincing methods with semen extender (Optixcell, IMV, France). The recovered spermatozoa with adjusted sperm concentration to $40{\times}10^6cells/mL$ was diluted with optixcell and cryopreserved. In experiment 1, the difference in the total number of spermatozoa using flushing and mincing methods was insignificant (2570.0 and $2505.2{\times}10^6cells/mL$, respectively). For experiment 2, the percentage of motile spermatozoa and motility parameters between flushing and mincing methods were studied through the use of sperm class analyzer after frozen-thawing. The percentage of total motile sperm between flushing and mincing methods was almost the same with $89.5{\pm}12.8$ and $91.4{\pm}7.9%$, respectively. The same is the case with experiment 3 wherein the viability and acrosomal integrity of frozen-thawed epididymal spermatozoa by flushing and mincing was insignificantly different. The results from the study showed that both flushing and mincing methods can be used for epididymal spermatozoa recovery in bull.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.307-316
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• 2022

The misuse of pesticides has resulted in environmental pollution, which directly or indirectly affects all life on earth. Chlorpyrifos is a chlorinated organophosphorus pesticide that is commonly used in agriculture. The aim of this study was to investigate the effects of chlorpyrifos on the fertilization function of boar spermatozoa. Sperm samples from boars were subjected to varying concentrations of chlorpyrifos from 10 to 200 µM for two incubation periods, 30 min or 2 hrs. The boar spermatozoa were then evaluated for motility, motion kinematics, viability, acrosome integrity, chromatin stability, and generation of intracellular reactive oxygen species (ROS). There was a significant percentage reduction in sperm motility and motion kinematic parameters after both incubation periods (p < 0.05). The proportion of viable spermatozoa decreased after incubation for 30 min and 2 hrs in a dose-dependent manner (p < 0.05). A significantly lower percentage of normal acrosomes was observed in spermatozoa exposed to 200 µM chlorpyrifos over both incubation periods, compared to the controls. The damage to sperm DNA was significantly higher when the exposure time to chlorpyrifos was longer. There was a significant increase in the ROS levels in spermatozoa incubated with chlorpyrifos for 2 hrs (p < 0.05). From the results of the present study, it is concluded that direct exposure of boar spermatozoa to chlorpyrifos altered boar sperm characteristics, suggesting potential toxicity that may affect the male reproductive function.

• Reproductive and Developmental Biology
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• v.36 no.3
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• pp.147-154
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• 2012

This study was designed to determine whether low-density lipoproteins (LDL) from egg yolk and taurine, hypotaurine and trehalose as antioxidant in extender improve the freezability and fertility of Korean Jeju Black Bull semen. The semen was cryopreserved with tris egg yolk extenders containing 7% glycerol and treated 4% LDL, 20 mM taurine, hypotaurine and trehalose. Frozen-thawed sperm were evaluated motility, viability, membrane, and acrosome integrity and sperm penetration ability. The results were compared to semen cryopreserved in tris egg yolk extender only as control. Frozen-thawed semen evaluation cleary indicated that the addition of LDL and LDL-antioxidants (taurine, hypotaurine and trehalose) combination were significantly improved (p<0.05) the viability (%; with staining test using eosin-Y) compared to control spermatozoa. Also, in membrane integrity (%; with supravital hypo-osmotic swelling test), not only LDL-antioxiants combination but also LDL were significantly increased (p<0.05) the swelled sperm using HOST compared to control. Sperm acrosome integrity state was classified by CTC (chlortetracycline) staining test. F pattern was significantly increased in LDL-antioxidant combination than control (p<0.05) and B pattern was not significantly differences among all treatments and control. However, AR pattern was significantly decreased in LDL-antioxidants combination than control (p<0.05). Pronucleus formation and sperm penetration index (SFI) were significantly increased in LDL and LDL-antioxidants combination than control (p<0.05). Especially, LDL-taurine significantly improved pronucleus fomation and SFI than LDL (p<0.05). It was concluded that LDL and LDL-antioxidants in extender improved the freezability and fertility of Korean Jeju Black bull spermatozoa.

• Journal of Life Science
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• v.30 no.1
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• pp.77-81
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• 2020

The aim of this study was to overcome some of the limiting factors that the maxi cryopreservation straw of 5 ml presents in processing boar semen. Cryopreservation of semen samples was conducted in 0.5 ml and 5.0 ml straws at two freezing rates: -140℃ in 8 minutes and 30 seconds (FR-1) and -140℃ in 14 minutes (FR-2). The straws were then thawed and the semen parameters were compared by Computer Assisted Sperm Analysis, and sperm morphology and acrosome status were examined by Coomassie blue staining. The effects of different thawing temperatures and durations were also compared, namely 37℃ for 115 sec, 50℃ for 45 sec, or 70℃ for 25 sec. In general, the FR-1 group showed higher (p<0.05) sperm viability and motility than the FR-2 group in the 5.0 ml straws. Compared to other ranges, thawing at 50℃ for 45 sec showed the highest sperm viability and motility (68.4±3.6% and 69.5±2.2%, p<0.05), suggesting that thawing temperature should be adjusted concurrently with freezing rate. Sperm morphology and acrosome integrity did not significantly differ among the groups (p>0.05). The data obtained in this study suggest that improving the freezing-thawing protocol for one artificial insemination dose straws (5.0 ml) retains the sperm's parameters from 0.5 ml cryopreservation, and is more convenient to handle, which could result in enhanced reproductive performance.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.2
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• pp.105-115
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• 2002

Objective : To evaluate the effects of the reactive oxygen species (ROS) generated with a xanthine (X) and xanthine oxidase (XO) system on sperm function, the change of sperm characteristics, lipid peroxidation, and DNA fragmentation in bovine spermatozoa. Materials and Methods: ROS were produced using a combination of 1000 uM X and 50 mU/ml XO. The ROS scavengers: superoxide dismu tase (SOD) (200 U/ml) and catalase (500 U/ml) were also tested. Spermatozoa were incubated for 2 hours in BWW medium with a combination of X-XO supplemented with or without ROS scavengers at $37^{circ}C$ under 5% $CO_2$ incubator. Sperm movement characteristics by CASA (computer-aided sperm analysis), HOST (hypoosmotic swelling test), Caionophore induced acrosome reaction, malondialdehyde formation for the analysis of lipid peroxidation, the percentage of DNA fragmentation using the method of TdT-mediated nick end labelling (TUNEL) by flow cytometry were determined after 2 hours incubation. Results: The action of ROS on bovine spermatozoa resulted in a decreased in capacity for sperm motility, Ca-ionophore induced acrosome reaction and membrane integrity, an increased in malondialdehyde formation and the percentage of sperm with DNA fragmentation. In the effects of antioxidant, catalase completely alleviated the toxic effects induced by the ROS in terms of sperm function and characteristics, however SOD exhibited no capacity to reduce the toxic effects. Conclusion: The ROS can induce significant damages to sperm functions and characteristics. The useful ROS scavengers can minimized the defects of sperm function and various damages of spermatozoa.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.507-515
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• 2009

A series of experiments were conducted to determine the suitable freezing and thawing temperatures for the freezing of boar semen in 5 ml maxi-straws. The ultrastructure, in vitro fertilization (IVF) and artificial insemination (AI) of frozen-thawed semen were also be evaluated. The 5 cm freezing height gave the best results not only in post-thaw motility rate (54.00%), but also in normal acrosome morphology rate (NAR) (80.23%). There was no significant difference in the post-thaw motility between different thawing temperatures and corresponding thawing times (p>0.05); the group of $52^{\circ}C$ and 25 s gave the highest motility rate (45.00%). As a whole, not only from the motility but also the NAR, thawing at $42^{\circ}C$ was better than the other two treatments. In the freezing packages, 5 ml maxi-straw gave a little lower mobility (40%), viability rate (49.58%), plasma membrane integrity rate (53.91%) and NAR (52.65%) than the 0.25 ml straw, but there was no significant difference between the two straw volumes (p>0.05). The IVF capacity of frozen-thawed semen in this experiment was similar to fresh semen. From ultrastructure observation, the main damage to boar spermatozoa after freezing was seen in the acrosome, such as swelling and formation of vesicles. After AI in recipient Shanghai White sows, frozen-thawed semen from 5 ml maxi-straws and pellets produced 72.2% and 80% conception rate and 7.8 and 8 litter sizes, respectively, and there was no significant difference between the 5 ml maxi-straw and the pellet (p>0.05).

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.175-179
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• 2007

The objective of this study was to investigate the effect of thawing temperature on the sperm viability and acrosomal morphology for semen storage of miniature pig by the 0.5ml straw method. In this present study, sperm viability (SYBR-14/PI staining), membrane integrity (Hypoosmotic Swelling Test), acrosome intactness, intensity and capacitation status (chlorotetracycline staining) in frozen miniature pig sperm were evaluated after thawing at 37, 50 and $70^{\circ}C$ for 5, 10 and 45 sec, respectively. Interestingly, the results indicated that sperm thawed at $70^{\circ}C$ for 5 sec significantly (p<0.05) increased sperm viability, but lower the percentage of AR (acrosome reacted spermatozoa) pattern compared to sperm thawed at $37^{\circ}C$ for 45 sec and $50^{\circ}C$ for 10 sec. In terms of thawing condition, high temperature for a short time using the 0.5ml straw was improved cryosurvival of miniature pig semen. Therefore, appropriate thawing method for cryopreservation of miniature pig is required for increasing post-thawing viability.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.377-383
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• 2011

The objective of this study was to examine effect of ethylene glycol for semen cryopreservation in Korean Jeju Black Bull. The semen was cryopreserved with extenders containing cryoprotectants (7% glycerol and 3%, 5%, 7% ethylene glycol) and packed to 0.5 ml straws. The semen straws were located above 3 cm of liquid nitrogen for 5 min, 5 cm for 10 min and 8 cm for 10 min. And then frozen straw was plunged into $LN_2$. Post-thawed sperm motility, viability and membrane integrity were significantly higher in 5% ethylene glycol ($72.5{\pm}5.00%$, $54.88{\pm}0.66%$ and $46.00{\pm}2.40%$; p<0.05). Motility and viability were similar between 7% glycerol and 5% ethylene glycol. However, the membrane integrity was significantly higher in 5% ethylene glycol ($34.69{\pm}4.64%$ vs $46.00{\pm}2.40%$; p<0.05). The viability and membrane integrity were significantly higher in 5 cm for 10 min and 8 cm for 10 min than 3 cm for 5 min (viability: $55.81{\pm}2.94$, $55.19{\pm}3.34$ vs $47.94{\pm}3.48%$; p<0.05 and membrane integrity: $44.94{\pm}3.51$, $46.06{\pm}2.25$ vs $40.38{\pm}1.03%$; p<0.05). The percentage of capacitated sperm assessed by CTC staining, percentage of F pattern was higher in 7% glycerol, 5% and 7% ethylene glycerol, and AR pattern was significantly higher in 3% ethylene glycol. F pattern was significantly increased in 5 cm for 10 min and 8 cm for 10 min (p<0.05), but AR pattern was significantly increased in 3 cm for 5 min (p<0.05).