• Asian-Australasian Journal of Animal Sciences
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• v.21 no.3
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• pp.340-345
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• 2008

Oxidative stress is one of the major causes of failure of in vitro storage of boar semen. Reactive oxygen species (ROS) are one of the important mediators of oxidative stress during in vitro storage of boar semen. Our study examined the effects of taurine on sperm characteristic and on in vitro developmental embryos during in vitro storage of boar semen for 7 days. Semen was randomly aliquoted into 3 centrifuge tubes and treated with different concentrations of taurine (25-100 mM). The characteristics of boar sperm were analyzed for motility by light microscopy, viability by using a Makler counting chamber and membrane integrity by a hypoosmotic swelling test (HOST). The percentages of motile spermatozoa in taurine groups after 5 days were significantly higher compared to the control. Sperm viability in the control was lower than in taurine groups after 7 days irrespective of different taurine concentration. In the hyoosmotic swelling test (HOST), significantly higher results were obtained in taurine groups after 3 days. Also, the developmental rates of IVM/IVF porcine embryos from semen treated with pyruvate and taurine were significantly increased when compared with the control (p<0.05). These results indicate that supplementation of taurine as an antioxidant in boar semen extender can improve the semen quality.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.203-207
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• 2011

The objective of this study was to determine the effect of semen extenders on the motility, viability and fertility in vitro of spermatozoa during storage of fresh boar semen diluted in different commercial extenders used for pig artificial insemination (AI). In this experiment, semen were diluted in Androhep plus, Beltsville Thawing Solution (BTS), Modena, Seminark and Vitasem LD. Five ejaculates were collected from three Duroc boars and sub-samples were diluted ($30{\times}10^6$ spermatozoa/ml) in different extenders. Semen was stored at $170^{\circ}C$ for 10 days. Sperm motility and viability was assessed using Computer-Assisted Semen Analysis (CASA) and flow-cytometry on 1, 3, 5 and 10 day post collection The motility of spermatozoa stored in different extenders was gradually decreased by increasing the duration of storage of semen. However, there was not significant1y different in the sperm motility and viability among other extenders. On the other hand, the in vitro-matured oocytes were fertilized and cultured in vitro to assess the fertility of boar spermatozoa stored for 3 and 10 days in different extenders. The percentage of morula and blastocyst were taken as indicators of fertility in vitro of spermatozoa. Therefore, there were no differences in the rate of embryos developed to the molular and blastocyst stage. There were no differences in the motility and fertility in vitro among 5 kinds of commercial boar semen extenders.

• Journal of Embryo Transfer
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• v.30 no.2
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• pp.109-114
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• 2015

Cryopreservation of boar semen is continually researched in reproductive technologies and genetic resource banking in breed conservation. For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Various researches have been trying to improve the quality of semen post-thawed in boar. Recently, polymorphism (g.358A>T) of cluster-of-differentiation antigen 9 (CD9) gene reported to be significant association with MOT. Also, CD9 gene was expressed in the male germ line stem cells is crucial for sperm-egg fusion, and was therefore selected as candidate gene for boar semen. This study was conducted to evaluate the pig SNP (g.358A>T) of CD9 gene as a positional controlling for semen parameters of post-thawed boar semen. To results, the g.358A>T SNP of the CD9 gene was significantly associated with the traits such as MOT, curve linear velocity, straight line velocity, average path velocity and amplitude of lateral head displacement. Particularly, the g.358A>T SNP significantly has the highest association with MOT and animals with AA genotype (p<0.001). Therefore, we suggest that the g.358A>T in the intron 6 region of the porcine CD9 may be used as a molecular marker for Duroc boar Post-thawed semen quality, although its functional effect was not defined yet.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.125-131
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• 2010

Bacterial contamination is an unavoidable finding of the semen collection process in boar and can lead in deleterious effects on semen quality and longevity if left uncontrolled. The purpose of this study is to identify the bacteria in extended boar semen and to select the effective antimicrobials to control of the contaminants. Of 116 extended boar semen samples submitted from eight AI centers in Korea, 39 (33.6%) samples were positive for bacterial contamination. Among 39 contaminated semen, most of them (84.6%) were contaminated with one or two bacterial species and there was no significant difference between two age groups $(\leq\;24\;and\;>\;24\;month\;old).$ Stenotrophomonas maltophilia (n = 18) was the most predominant bacterium followed by Elizabethkingia meningoseptica (n = 12), Sphingomonas paucimobilis (n = 12), Myroides spp. (n = 5), Ochrobactrum anthropi (n = 3), and so on. Enrofloxacin (72.9%), florfenicol (72.9%), bacitracin (49.2%) and tylosin (49.2%) showed higher sensitivity compared with penicillin (13.6%) or aminoglycosides (6.8%-18.6%). Brucella spp., Leptospira spp., Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycobacterium tuberculosis complex were not detected in semen by PCR.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.143-147
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• 2015

Cryopreservation of boar semen is continually researched in reproductive technologies and genetic resource banking in breed conservation. For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Various researches have been trying to improve the quality of semen Post-thawed in boar. Recently, polymorphism (g. 35756 T>C) of Estrogen Receptor 1 (ESR1) gene reported to be significant association with MOT. This study was conducted to evaluate the ESR1 gene as a positional controlling for motility and kinematic characteristics of post-thawed boar semen. To results, The g.35756 T>C SNP of ESR1 was significantly associated with frozen semen motility and kinematic characteristics. The g.35756 T>C SNP was high significantly associated with MOT, VCL, VSL and VAP (p<0.001). The SNP was also significantly associated with ALH (P<0.05). Therefore, we suggest that the g. 35756 T>C polymorphism in the intron 1 region of the porcine ESR1 gene could potentially be applied in frozen semen programs to improve MOT trait, but only after validation in other populations.

• Journal of Life Science
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• v.33 no.7
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• pp.586-592
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• 2023

Oxidative stress is a critical factor affecting the quality and viability of sperm during boar semen storage. Oxidative stress is also a significant concern during the process of freezing semen. The process of semen storage involves exposing the sperm to various stressors, including temperature changes, cryoprotectants, and extended periods of incubation. In addition, oxidative stress can lead to the production of reactive oxygen species (ROS) within the sperm, resulting in oxidative damage to cellular components, such as lipids, proteins, and DNA. Striking a balance between ROS production and the antioxidant defense system is crucial for maintaining sperm viability and functionality during semen storage. Moreover, the prolonged storage of boar semen leads to an increase in ROS levels, which can impair sperm motility, membrane integrity, and DNA integrity. ROS-induced lipid peroxidation affects the fluidity and stability of sperm membranes, leading to decreased sperm motility. Moreover, oxidative damage to the DNA can result in DNA fragmentation, compromising the genetic integrity of the sperm. In conclusion, oxidative stress is a significant challenge in maintaining sperm quality during boar semen storage. Understanding the mechanisms underlying oxidative stress and their impacts on sperm function is crucial for developing effective strategies to minimize oxidative damage and improve sperm storage outcomes.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.486-494
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• 2006

In order to protect the spermatozoa against cold shock, hen egg yolk is widely used as a cryoprotective agent in semen freezing extenders for domestic animals. The protective action of yolk is largely presumed to be due to low density lipoproteins (LDL). The effects of LDL on sperm quality of bull and northern pike (Esox lucius) after freezing-thawing have been reported, but no study has been made to evaluate the effect of LDL on boar sperm motility and other characteristics. The experiment was carried out to investigate the effect of LDL on the freezing of boar sperm in 0.25 ml straws. The aim was to evaluate the quality of boar spermatozoa cryopreserved in the presence of LDL. Motility of semen cryopreserved in LDL was analyzed and compared to semen cryopreserved with Tris-citric acid-glucose (TCG) and Tris-citric acid-fructose (TCF), two basic freezing extenders containing egg yolk. Similarly, acrosome and plasma membrane integrity were also evaluated and compared to semen cryopreserved with TCG and TCF. Analysis of sperm quality after freeze-thaw showed that the motility, acrosome and plasma membrane integrity were improved with LDL in the extender, as compared to the TCG and TCF. The highest post-thaw integrity of acrosome and plasma membrane and motility were obtained with 9% LDL (w/v). Consequently, the optimum LDL concentration in the extender was 9%. It is also suggested that the concentration of LDL addition is important for the effect on boar sperm protection during freezing and thawing. The percentage of motile spermatozoa was significantly higher after freezing in 9% LDL than in TCG and TCF 54.4% versus 30.4% and 30.1% (p<0.05), respectively. The integrity of acrosome and plasma membrane were also significantly higher at 70.3% and 50.5% respectively with semen frozen in 9% LDL extender compared to TCG at 37.8% and 30.3% and TCF at 36.4% and 29.9%, respectively (p<0.05),. In conclusion, we propose that extender containing LDL extracted from hen egg yolk could be used as a cryoprotective media with a better efficiency than TCG and TCF. LDL improved boar semen quality, allowing better spermatozoa motility, acrosome and plasma membrane integrity after the freeze-thaw process. Furthermore, we found out that the extender with 9% LDL concentration significantly enhanced motility, acrosome and plasma membrane integrity of boar sperm after freezing and thawing.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1417-1425
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• 2014

The selection of morphologically normal spermatozoa is critical to obtain high breeding performances in boar breeding farms and artificial insemination (AI) centers. Parameters for the selection of semen mainly include total sperm motility, concentration, and morphology. However, these primary parameters are often not reliable for discriminating between normal and abnormal, non-fertilizable spermatozoa. The present study was designed to compare the motion characteristics, fertilization ability using in vitro fertilization (IVF), and acrosome formation of the semen from boars having low (boar number 2012) and normal (boar number 2004 and 2023) breeding performances. The ultimate goal was to identify additional simple and easy criteria for the selection of normal sperm. There was no significant difference between boar 2004 and boar 2023 sperm total motility in computer assisted sperm analysis. However, boar number 2012 semen presented a significantly reduced population of rapid moving spermatozoa and an increased population of slow moving spermatozoa compared to boar numbers 2004 and 2023. Analysis of detailed motion characteristics revealed that sperm from boar number 2012 had significantly reduced motility in progressiveness, average path velocity, straight-line velocity (VSL), curvilinear velocity (VCL), straightness, and linearity. The assessment of the fertilizing ability by IVF also showed that sperm from boar number 2012 showed a fertility rate of 3.4%, whereas sperm from boar number 2023 had a fertility rate of 75.45%. Interestingly, most of the sperm nuclei were found on the peripheral area of the oocytes, suggesting that the sperm from boar number 2012 lacked penetration ability into the oocyte zonapellucida. The acrosome formation analysis using Pisum sativum agglutinin staining demonstrated that the sperm from boar number 2012 had a defect in acrosome formation. Consequently, primary parameters for selecting semen before AI such as motility are not sufficient to select normal and fertilizable spermatozoa. In conclusion, the present study suggests that the acrosome staining and detailed motion characteristics such as progressiveness, VCL, and VSL should be included in determining semen quality together with primary parameters for successful AI and high breeding performance in the swine industry.

• Journal of Embryo Transfer
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• v.14 no.2
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• pp.131-137
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• 1999

This experiment was carried out to investigate the effects of osmolarity of thawing diluents, seminal plasma added in thawing diluents on the sperm viability and the effects of thawing temperature, the temparature of the thawing diluents on the sperm viability and acrosomal morphology of boar spermatozoa by the straw method. The result obtained were summarized as follows: 1. The sperm viablilty after thawing of the frozen semen was shown greater in the high osmolarity(392~492mOsm) than low osmolarity(300mOsm) in thawing diluent. The added levels of seminal plasma in thawing diluent did not affect the viability of frozen-thawed boar semen. 2. In terms of thawing temperature, the sperm viability was shown higher in the frozen semen thawed at 5$0^{\circ}C$ for one min. (p<0.01) than those thawed at 2$0^{\circ}C$ or 37$^{\circ}C$ for one min. The sperm viability was not significant at the diluent temparature of 2$0^{\circ}C$or 37$^{\circ}C$ after thawing: but the sperm viability was higher in thawing diluent at 2$0^{\circ}C$ than in that at 37$^{\circ}C$. However, the effects of thawing temperature and diluent solution on normal acrosomal rate were not significant. 3. Cleavage rates of oocytes fertilized with frozen semen were 46.4% and 43.3%, respectively, which were thawed at 5$0^{\circ}C$ for one min. and then diluted in mBTS medium at 2$0^{\circ}C$or 37$^{\circ}C$. To sum up, the sperm viability was shown greater at the high of thawing diluents of frozen boar semen. In terms of thawing conditions, the sperm viability was shown greater, when semen was thawed at a high temperature for a short time and then diluted at the same temperature as that in the straw.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.401-411
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• 2023

Many studies have been conducted to improve technology for semen cryopreservation in pigs. However, computer-assisted analysis of sperm motility and morphology is insufficient to predict the molecular function of frozen-thawed semen. More accurate expression patterns of boar sperm proteins may be derived using the isobaric tags for relative and absolute quantification (iTRAQ) technique. In this study, the iTRAQ-labeling system was coupled with liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis to identify differentially expressed CM10-fractionated proteins between fresh and frozen-thawed boar semen. A total of 76 protein types were identified to be differentially expressed, among which 9 and 67 proteins showed higher and lower expression in frozen-thawed than in fresh sperm samples, respectively. The classified functions of these proteins included oxidative phosphorylation, mitochondrial inner membrane and matrix, and pyruvate metabolic processes, which are involved in adenosine triphosphate (ATP) synthesis; and sperm flagellum and motile cilium, which are involved in sperm tail structure. These results suggest a possible network of biomarkers associated with survival after the cryopreservation of Duroc boar semen.