جستجوی مقالات مرتبط با کلیدواژه « ram » در نشریات گروه « علوم دام »

The present study was conducted in order to use different levels of curcumin in the diluting sperm epididymis of Shal breed rams during storage at five degrees Celsius in the form of a completely randomized design with four treatments in six replications. Sperm samples were extracted from the testicular tissue and used in the Tris-egg yolk diluent. Different concentrations of curcumin including 0, 10, 25 and 50 μM were added to the diluents. The samples were gradually cooled at 5°C and after stabilization at this temperature, in 6, 12, 24 and 48 hours, the parameters of total motility, progressive motility, viability, membrane integrity and the percentage of sperm abnormalities were evaluated. The results showed that the use of 25μM curcumin improved the parameters of total motility, progressive motility, viability and membrane integrity only at 6 and 12 hours, but no significant difference was observed at 24 and 48 hours compared to other treatment groups. Regarding sperm abnormalities, no significant difference was observed between the treatments in all the examined times. The results of this study indicate that using a concentration of 25μM curcumin can lead to the improvement of ram epididymal sperm quality in the initial periods of storage, but it loses its effect in longer periods of time. Therefore, it is recommended to use nanotechnology methods to improve the effectiveness of curcumin, especially during long-term storage of ram sperm.

Sperm cryopreservation is a highly effective technique utilized in reproductive procedures, particularly in artificial insemination, as it enables the transfer of superior genes to the subsequent generation of animals. However, the exposure of sperm cells to low temperatures during the freezing process can have detrimental effects on their integrity, morphology, and viability (Gangwar et al., 2020). To counteract these negative impacts, cryoprotectants are added to the sperm extender. The primary purpose of incorporating cryoprotectants is to fulfill the energy requirements of the sperm, shield them from the adverse consequences of temperature fluctuations, mitigate the physical and chemical stresses associated with cooling, freezing, and thawing, and create an environment conducive to enhancing sperm survival (Barbas and Mascarenhas, 2009). In recent years, plant-based extenders have emerged as a viable alternative to animal-based extenders for semen preservation in various species. Coconut milk, in particular, has garnered attention due to its rich composition of fatty acids (including polyunsaturated fatty acids), amino acids, sugars, antioxidants, vitamins, and minerals. These components not only provide essential nutrients for maintaining cell function but also serve as a suitable medium for sperm extension and culture (dos Reis et al., 2023; Vasconcelos et al., 2009; Yong et al., 2009). Consequently, this research aims to explore the impact of coconut milk on the quality of ram sperm following cryopreservation. Twice a week, semen samples were obtained from five Lori-Bakhtiari rams using an artificial vagina. The collected semen from these five rams was then combined and divided into six different treatments. These treatments consisted of five variations with varying levels of coconut milk (5%, 10%, 15%, 20%, and 25%) and one treatment with egg yolk (15%). Various parameters such as sperm velocity, membrane integrity and activity, morphology, lipid peroxidation rate, and sperm DNA fragmentation were assessed both before and after the process of cryopreservation. The obtained data was subsequently analyzed using the SAS statistical software. Prior to cryopreservation, the results indicated that, with the exception of the BCF parameter, there were no disparities in the various aspects of sperm kinetics, viability, functionality, and morphology. However, a notable decline in sperm motility parameters was observed after thawing across all treatments. This detrimental impact following the freezing process was more pronounced (P<0.05) when using the extender containing coconut milk compared to the extender containing egg yolk. Consequently, in terms of other motility parameters, the egg yolk treatment exhibited significantly higher values (P<0.05) than the other treatments, except for VCL (94.36±10.41%) and BCF (5.83±0.70 Hz). The findings of Wojtusik et al. (2018) were in line with the results obtained in this study. It was observed that when coconut water and coconut milk were used as substitutes for egg yolk in rhinoceros sperm extenders, there was a decrease in both sperm motility and viability. Similarly, the use of powdered coconut water as an extender for cryopreservation of cat sperm resulted in a significant reduction in sperm movement quality compared to a tris extender (de Sousa Barbosa et al. 2020). Furthermore, when comparing different alternatives to egg yolk in the extender of rhinoceros sperm, such as soy lecithin (1 and 2%), coconut water (20%), and coconut milk (20%), it was found that the extenders containing coconut milk or water led to a loss of sperm mobility and viability. However, the extenders containing soy lecithin showed more promise as substitutes for egg yolk, as they maintained sperm viability, morphology, and acrosome integrity better than coconut milk and water (Wojtusik et al., 2018). In contrast to the findings of this investigation, the utilization of extenders comprising powdered coconut water for the cryopreservation of sperm in various animal species, including dogs, boars, horses, goats, and fish, resulted in well-preserved sperm morphological and motility parameters following the freeze-thaw process. Furthermore, studies have demonstrated that freezing goat sperm with coconut milk, bull sperm with coconut oil, and equine and boar sperm with coconut water led to enhanced sperm viability and quality compared to control groups. The ineffectiveness of the extender may be attributed to the presence of salts and ions, such as calcium, potassium, and sodium, in coconut water, which could potentially interact with the channel proteins of the sperm cell plasma membrane. It is important to note that the precise mechanism by which coconut products in the extender maintain sperm characteristics remains unknown. Previous research by Toniolli et al. (1996) suggested that coconut water may serve as a protective agent for sperm due to its content of 3-indoleacetic acid. Furthermore, the replacement of glycerol with dimethylformamide in the boar sperm extender resulted in better preservation of sperm quality after the freezing and thawing process compared to other treatments (Silva et al. 2015). This suggests that each ingredient present in an extender could have a significant impact on enhancing extender efficiency. It is worth noting that coconut milk contains high levels of polyunsaturated fatty acids, which can make sperm more vulnerable to oxidative stress (dos Reis et al., 2023; Vasconcelos et al., 2009). However, no significant differences were observed in the lipid peroxidation indicator and the DNA fragmentation index among the various extenders used in this study. This could indicate that the extenders had similar antioxidant properties. The variations in the reported findings may be attributed to differences in the combinations and quantities of products used in the extenders, the type of base extender employed, variations in semen combinations and the sensitivity of sperm in different animal species, or discrepancies in the coconut combinations utilized (dos Reis et al., 2023). This research suggests that substituting egg yolk with coconut milk entirely in a ram sperm extender does not mitigate the negative consequences of cryopreservation. Additional investigations are necessary to determine the specific composition of the extender incorporating coconut-based ingredients for the cryopreservation of ram sperm.

Dietary supplementation of trace minerals (zinc, copper and manganese) has positive effects on various aspects of reproductive performance of farm animals and it has a strong antioxidant effect on sperm function. Also, feeding with trace minerals affects the functional structure of sperm cells and increases the quality of sperm for cryopreservation because it may lead to cell damage, production of reactive oxygen species and reducing the antioxidant capacity of seminal plasma. The objective of this study was to investigate whether dietary supplementation of zinc, copper and manganese affected on sperm motion characteristics, percentage of viability, sperm membrane integrity after thawing, and flow cytometry tests including apoptosis, hydrogen peroxide and molecular oxygen. Ten mature Afshari rams were all fed a nutritionally adequate diet for 70 days, from the end of September to the beginning of December. Half of the rams were randomly designated to receive dietary supplementation with a sulfate source of zinc, copper and manganese once daily for 70 days, starting 1 week after the study began. All ejaculates were diluted with a Tris-based cryoprotective extender. The extended semen was subsequently loaded into 0. 5 mL plastic straws and then they were frozen by the bio-freezer machine. One week after freezing, three straws of each ram were thawed and evaluated for sperm motion characteristics by computer-assisted-semen-analysis system, hypoosmotic swelling test and live sperm percentage. In addition, we examined hydrogen peroxide, molecular oxygen and apoptosis in frozen sperm. Proc Mixed was used for analysis of repeated measures data. Motion characteristics, percentage of sperm viability and sperm membrane integrity after thawing in the Supplemented group was relatively stable and significantly higher than in the Control group from day 28 onwards (P<0/05). At the end of this research, the levels of hydrogen peroxide, molecular oxygen, early apoptosis, late apoptosis and necrosis in the control group were significantly higher than the Supplemented group (P<0/05). The average number of live sperm in the Supplement group increased slightly at the end of the research period outside the breeding season, but it was not significant compared to the beginning of the period, but this rate at the end of the period was significantly higher than that of the Control group (P<0/05). The results showed that the simultaneous supplementation of zinc, copper and manganese elements, even after the reproductive season, can have beneficial effects on the quality and freezing ability of sperm after thawing and prevent the creation of reactive oxygen species and the occurrence of apoptosis.

The need for artificial insemination in the ewe is to access fresh and frozen sperm. Cryopreservation is a suitable method for long-term storage of semen and sperm, but may cause a minor irreversible damage to the sperm cell, especially its membrane region (Khorramabadi et al., 2017). The oxidation of fatty acids leads to the production of free oxygen radicals (ROS). These radicals are necessary in normal conditions for certain physiological activities and sperm processes, but excessive production of ROS in the sperm can reduce membrane fluidity, DNA fracture, damage to proteins, and ultimately reduced sperm motility and fertility. (Bakhshayesh et al., 2017). Silymarin, the scientific name of Silbum marianum, is the English name Milk Thistle and is a potent inhibitor of oxidative stress as a potent antioxidant. Due to the nature of its friend fat, silymarin is firmly attached to the plasmid membrane compounds, thus preventing fracture and its collapse by increasing membrane strength. Increasing the amount of active oxygen species and lipid peroxidation disrupts mitochondrial membrane, decreases ATP and damage to sperm acesomes, which ultimately reduces the progression of sperm motility. (Kvasnikova et al., 2003). The mechanism of action of salimarin is through stimulation of the ribosomal RNA and protects the membrane from oxidative damage. They also stated that silymarin stimulates the activity of the antioxidant enzymes of superoxide dismutase (SOD) and glutathione peroxidase (Wellington and Jarvis, 2001) . Silymarin improves the sperm motility and survival, sperm abnormalities, and preservation of the sperm membrane after freezing-thawing. Improvement of semen quality in both freezing and cooling is due to the strong silicomain antioxidant capacity (Fakorzai et al., 2008; Longpyram et al., 2013). .

Regarding the anti-oxidant effects of silymarin, this study aimed to investigate the effect of silymarin on storage of ram sperm.

In this research, four rams of pure ghee were used 2-3 years old and each ram was 6 times sperm. Sperm was performed twice a week by artificial vagina. After the sample was transferred to the laboratory, a series of preliminary evaluations including sample size, sample color, wave motion, total mobility, in-situ motion, progressive motion and live weight, and abnormal sperm and density were performed. If standards were met, Necessary (scaling over 2.5 billion sperm and progressive movement above 70%) dilution was performed with treatments. The diluents were prepared prior to sampling and placed in a bin Marie temperature of 37 ° C. Tris-based diluent was used to contain 2.73 g of tries, 1.4 g of fructose, 1 g of citric acid and 100 mg streptomycin in 100 ml sterile distilled water. To prepare the diluent, 73% of the prepared solution will be mixed with 20% egg yolk and 7% glycerol. In order to dilute the sprays from trace based diluent, egg yolk, semen collected with diluent without antioxidants (control) and silymarin 5 and 10 μg / ml mix After cooling for 90 minutes in the refrigerator and reaching 5 ° C, it was placed in 4 cm above the liquid nitrogen for 8-10 minutes and then immersed in liquid nitrogen. The post-mortem examinations of sperm quality properties included liveliness, total motion, progressive motion, integrity of the plasma membrane (tests) on days 0, 15, 30 of the experiment.

According to the results of the experiment, the diluents containing the levels of silymarin significantly increased the total motion, progressive, live survival of ram sperm after the freeze-thawing process compared to the control group Were opened. Addition of different concentrations of silymarin was 5 and 10 μg with mean of 74.45% and 67.33%, respectively, compared to the control group, significantly increased the total sperm motility with mean of 68.07 and 60.95%, significantly Progressive motility of frozen ram sperm were frozen (p <0.01). According to the results, the in situ movement in the control group (5.92 ± 0.92) was lower than that of the 5 and 10 μg silymarin (6.38 ± 0.92) and (8.9 ± 0.92) respectively In the least amount.

Application of silymarin as an antioxidant in the ram sperm diluent system reduces oxidative damage and improves sperm quality properties such as mobility, viability and the health of acrosome and plasma membrane during freezing process. Was opened. Adding 5 μg of silymarin to diluted ram minus 10 μg and control group reduced fat peroxidation and also improved the structure and performance of sperm during storage.

Some previous researches have shown that dietary supplementation with some vitamins and trace elements can increase the ability of animals semen preservation during liquid storage or freezing. Therefore, the aim of this study was to investigate the effect of dietary supplementation of organic selenium and chromium on ram semen quality during liquid storage at 4 °C.

Numbers of 16 Mehraban rams, with ages ranging from 2-4 years and 69.75±10.44 kg average body weight, were divided into four groups of four and were fed by a basal diet consist of 70% forage and 30% concentrate. The experimental design was 2×2×4 factorial experiment based on randomized complete block design. The experiment lasted for 60 days. In this experiment, three factors were including selenium at two levels (0 and 600 µg/day/ram selenium as yeast-selenium), chromium at 2 levels (0 and 1000 µg/day/ram chromium as chromium-methionin) and time at 4 levels (0, 24, 48 and 72 hours after storage). Chromium was fed to rams using edible capsule shells and also selenium by drencher after dissolving in distilled water. In the last three weeks of the experiment, semen samples were collected 3 times. Semen samples after collection was diluted with tirs-egg yolk base extender and stored at 4°C for 72 h. Sperm cells viability, membrane integrity, abnormal morphology, total motility and progressive motility and some motion parameters is detected by computer-assisted sperm analysis at 0, 24, 48 and 72 hours after storage.

The effects of chromium, time and their interaction and also selenium × chromium interaction, selenium × chromium × time interaction were significant for sperm viability and membrane integrity (p < 0.05). The effect of selenium and selenium × chromium interaction was not significant for viability (p>0.05) but, the effect of chromium, selenium and time and also their interaction for membrane integrity was significant (p < 0.05). The viability reduced over time significantly (p < 0.05) and sperm viability in rams receiving the diet contained 1000 μg chromium, was higher than diet without chromium after storage at 4°C for 48 and 72 hours (p < 0.05). In addition, sperm viability in rams receiving the diet contained 600 μg selenium was higher than diet without selenium after storage at 4°C for 48 hours (p < 0.05). Adding 1000 μg chromium to diet containing 600 μg selenium, increased significantly sperm viability after storage at 4°C for 48 and 72 hours (p < 0.05). The membrane integrity reduced over time significantly (p < 0.05) and sperm membrane integrity in rams receiving the diet contained 1000 μg chromium was higher than other groups after storage at 4°C for 24 and 48 hours (p < 0.05). The effect of selenium and chromium and also their interaction was not significant for computer detected parameters (p < 0.05). Interaction of selenium and chromium for abnormal morphology was significant (p < 0.05) but the effects of chromium, selenium, time and their interaction was not significant (p>0.05). Total motility, velocity in curvilinear line, velocity in straight line, velocity in average path decreased over time during semen storage at 4°C (p < 0.05) and diet supplementation of selenium and chromium did not change these parameters (p>0.05). Progressive motility, abnormal morphology and straightness did not affected by time, selenium and chromum.

Generally, dietary supplementation of organic selenium and chromium in rams leads to increased sperm viability and membrane integrity during chilled liquid storage. Dietary supplementation of selenium and chromium did not change computer detected parameters during semen storage at 4°C. In general, the use of organic selenium and chromium in the diet of rams may increase the ability of sperm storage for artificial insemination.

According to an increasing interest for using artificial insemination by sheep producers, finding methods to maintain frozen semen fertility would be important and applicable. One of the freezing semen disadvantages is increasing of free radicals led to enhanced sperm membrane peroxidation then consequently causes lowered semen fertility after thawing. Some plants bearing high levels of plant antioxidants can help to decrease semen peroxidation. Cysteine, in addition, is a precursor of glutathione peroxidase being the most important antioxidant property in semen. Therefore, the aim of the study was to investigate the effect of adding different levels of ethanol extract of Mentha Longifolia (0, 100 and 200 microL/ml) and cysteine (0, 5 and 10 mmol/l) into ram semen on fertility features after freezing and thawing processes.

In the study, semen samples were collected from four mature, fertile Baluchi rams (> 2y-old) by artificial vagina and after initial evaluation were pooled together. Then, samples were extended in an extender based on Tris-egg yolk. Treatments were arranged as a 3×3 factorial experiment including nine treatments and six straws were assigned to each as replicate. After treating, the straws were filled by the equal amount of semen and after chilling in refrigerator (4 °C) for two hours were frozen in liquid nitrogen container. After thawing the straws at day 10, sperm motility parameters were assayed by CASA. Furthermore, the percentages of viability, plasma membrane integrity and normal morphology of sperms were evaluated by microscope. Data were analyzed by SAS software using GLM procedure and the means comparison was performed by Tukey-Kramer test at 5% error.

Results of the study showed that the effects of adding horsemint extract and cysteine into the extender and the interaction between them on the all motility and viability parameters of frozen ram sperm after thawing were significant (p<0.05), exempt for sperm morphology where only the effect of adding cysteine was significant. Means comparison showed that the greatest sperm total motility, plasma membrane integrity, linearity and curvilinear velocity were observed in cysteine10 treatment (without horsemint extract), while the greatest sperm viability, straight line velocity and average path velocity were seen in cysteine5 treatment (without horsemint extract). The greatest sperm progressive motility percentage was observed in horsemint200 group (without cysteine).

In general, considering to the beneficial effect of adding cysteine into the extender based on tris- egg yolk on the most of fertility parameters of ram frozen semen after thawing, using levels of 5 and 10 mmol cysteine per ml extender in order to maintain fertility of frozen ram semen is recommended.

This experiment was designed to evaluate the protective effect of nano-hydroxyapatite against freezing damages on spermatozoa using five rams. Ejaculates (N=30) were collected with three-day intervals between sessions for six times. Ejaculates were pooled and split into 12 parts at each session. The amount of 0.01, 0.02, 0.05 or 0.1% nano-hydroxyapatite and 3, 5 or 7% glycerol were added. Samples were frozen and stored for two weeks. After that two straws from each treatment for each replication (totally 144 straws) were thawed and incubated at 37 ° C for 6 h. Sperm motility, viability, membrane integrity and acrosome integrity were evaluated at 0, 3 and 6 h after thawing. Results showed that there was no interaction between nano-hydroxyapatite, glycerol and incubation time (P>0.05). Sperm viability and acrosome integrity were not affected by different levels of nano-hydroxyapatite particles (P>0.05). There was no difference between the level of 0.01 and 0.1% nano-hydroxyapatite particles on the total (21.8 and 21.5%, respectively) and progressive sperm motility (17.8 and 17.7 %, respectively; P>0.05). Total and progressive sperm motility was the highest (24.8 and 21.0%, respectively) in the level of 0.02% nano-hydroxyapatite particles (P<0.05). Membrane integrity was higher in the level of 0.02% nano-hydroxyapatite particles (52.7%) than other levels (P<0.05). Therefore, the addition of 0.02% nano-hydroxyapatite particles to the ram semen extender improved the quality of frozen spermatozoa.

The use of cryopreserved semen in artificial insemination (AI) has numerous advantages for the animal husbandry, especially when used in breeding programs. Long-term storage of sperm in liquid nitrogen is a valuable technique for genetic resources preservation (Mazur et al., 2008). Animals are transported frequently and widely around the world, and it is necessary to create and maintain suitable conditions during animal transportation (Salamon and Maxwell, 2000). However, the costs, the risks of escape, and the potential for accidental death of animals are unavoidable. On the other hand, cryopreserved sperm can be transported in liquid nitrogen at a markedly lower cost and without the risk of escape or death of animals (Aires et al., 2003). Numerous investigations have been performed to improve the protocols for cryopreservation of sperm. The extenders used for semen cryopreservation protect the sperm against thermal shock, preserving both motility and fertility by promoting the stabilization of the plasma membrane, and providing energy substrates (Amirat et al., 2004). These attributes reduce the deleterious effects of changes in the pH and osmolarity, prevent the growth of bacteria, and protect the sperm cells from the damage caused by refrigeration, freezing, and thawing. For sperm cryopreservation, protocols using egg yolk have been successfully established and applied in various animal species (Aisen et al., 2002). However, the use of egg yolk in cryopreservation has been questioned, because of certain potential negative aspects. Egg yolk contains a wide variety of compounds that are both beneficial and also potentially harmful to sperm. Additionally, egg yolk introduces a risk of contamination by microbes that can subsequently produce endotoxins; and so, the egg yolk and sperm are subjected to quarantine inspection in the case of import or export. Therefore, a replacement for egg yolk with a well-defined chemical composition would be very advantageous. Lecithin, also known as phosphatidylcholine, is a component of egg yolk and is known to prevent cold shock during the freezing and thawing process in sperm cryopreservation. Soybean lecithin in particular has already been used as a replacement for egg yolk in sperm cryopreservation in various animals. Its non-animal origin and minimal sanitary risks make it preferable for this application. Soybean Lecithin can be used as an extender in the cryopreservation process (Akhter et al., 2012). The aim of this study was to evaluate the effects of Soybean Lecithin as extender on the ram semen quality after freeze-thawing. Semen was collected from the indigenous Ghezel rams. Twenty five ejaculates were collected throughout the entire study, with semen being collected twice a week (every Sunday and Tuesday) from each ram, using the artificial vagina. Ejaculates were collected in graduated test tubes, placed in a thermo flask at 34°C, and transported to the laboratory for evaluation within 1h interval. The raw or fresh undiluted semen was then microscopically evaluated for volume, concentration, and sperm motility. The sperm concentration was determined with the aid of a neubauer lam. A Computer Assisted Sperm Analysis (CASA) system was used to evaluate the different sperm motility characteristics. All data were analyzed using the statistical procedure of SAS (version 9.2). The analysis of variance (ANOVA) was used to test for significant differences between treatments. Characterization of the Ghezel ram sperm viability (percentage live/dead) of the semen samples was determined using an eosin/nigrosin stain (50μl eosin/nigrosin and 5μl semen). The volume of the ram ejaculates ranged between 0.75 and 1.5mL. The sperm concentration recorded in this study ranged between 0.9 and 1.3 × 109 sperm/mL. The effect of different soybean lecithin levels on the Ghezel ram semen characteristics following cryopreservation was evaluated. After initial evaluation of the ejaculates, all ram ejaculates were pooled and semen sample was then divided into three portions; then, semen samples were diluted with soybean lecithin (1, 1.5 and 2 %) citrate extender and cooled over a period of 2h to 5°C. The semen samples were equilibrated for 2h and then loaded into 0.25mL semen straws. The straws were frozen in liquid nitrogen (LN2) vapor, then semen straws were plunged into the LN2 (-196°C). The semen straws were thawed 30 days later, in a water bath (37°C) for 30 seconds. The sperm characteristics included motility and motion parameters, viability, plasma membrane and acrosome integrity, sperm abnormality, and lipid peroxidation were evaluated. Motility and velocity were microscopically evaluated using the Sperm Class Analyzer® (CASA) system. This study demonstrated that soybean lecithin (1.5%) containing 7% glycerol can be used to cryopreserve Ghezel ram semen effectively, based on the sperm motility characteristics. The low sperm motility results recorded when semen was cryopreserved in soybean lecithin (2%). The results showed that total motility and some sperm motion parameters (VSL, VCL, VAP and ALH) were significantly higher in 1.5% lecithin soybean treatment group (P <0.05). In terms of survival, the percentage of abnormal sperm, plasma membrane integrity, and lipid peroxidation were not significant between treatments. Acrosome membrane integrity of 1.5% soybean lecithin treatment group was higher than other treatments (P< 0.05). Briefly, 1.5% soybean lecithin treatment had better performance than other levels on the quality of the sperm after freeze-thawing.

The purpose of this study was to compare the effect of different levels of zinc sulfate on improving the quality of ram semen during freeze-thawing process outside of the reproductive season. Semen samples were collected from five Ghezel ram twice a week using the artificial vagina. Sperm samples were assigned to four treatment groups including: control, 17.5, 35 and 52.5 μm zinc sulfate, and then the freezing process was performed. After thawing motility, morphology and malondialdehyde levels of sperm were studied. Total and progressive motility of sperm containing the 17.5 µmol/ml zinc sulfate were significantly higher than control group (P <0.05). There was a significant difference in sperm morphology in the group receiving 52.5 μmol of zinc sulfate compared to the control group, which caused 52.5% increase in abnormal sperm (P <0.05). Adding 17.5 μmol of zinc sulfate increased unsignificantly the viability of sperms compared to the control group, but adding 35 and 52.5 μmol decreased significantly (P <0.05). The level of malondialdehyde production in the 35 µmol was lower than the other treatment groups and the control group and there was a significant difference between the groups 17.5 and 35 in comparison with the control group (P <0.05). Therefore, it can be concluded that the use of 17.5 and 35 µmol Zinc sulfate in Ghezel ram diluent semen improves some of the parameters of the sperm after the freeze-thawing process.

The objective of this study was to investigate the effect of different levels of L-Carnitine on Ghezel ram semen characteristics after freeze-thawing. Semen samples were collected from 5 healthy and mature rams using an artificial vagina. Different concentrations of 35, 70, 105, mM L-Carnitine were diluted with lecithin-based semen extender and cooled to 5°C and then placed in liquid nitrogen vapor and finally were stored in liquid nitrogen tank. The experiment was carried out on the basis of completely randomized design with 5 replicates. The results showed that the highest total motility and progressive motility were observed in groups containing 70 and 105 mM L-Carnitine that were not significantly different from the control group. The lowest motility recorded in this experiment was the first level of L-Carnitine. In other parameters only VAP, ALH, VCL and LIN were significantly different from the control group. The first level of L-Carnitin was statistically significant in morphology compared to the control group. Addition of 105 mM of L-Carnitine caused higher membrane integrity and lower MDA level compared to 35 mM group (p

Today, artificial insemination plays an important role in improving production efficiency and improving genetic progress. In order to realize many of the potential benefits of artificial insemination, semen storage for a long-term is considered a necessary step by freezing process. The freezing process, including the freezing process, leads to morphological changes, damage to the natural functions of the sperm and ultimately reduced fertility. Therefore, improving the thawing method of ram semen is related to the sperm quality indicators and is of considerable importance. The purpose of this study was to compare the effects of two thawing rates on microscopic parameters and enzyme activity of ram semen after freeze-thawing process. In this study, semen samples were collected from five Ghezel ram using an artificial vagina twice a week. To eliminate the individual effects of animals, semen samples were pooled after each sampling. Then diluted with Tris diluent. The diluted semen samples were frozen in nitrogen vapor and eventually stored in a tank containing liquid nitrogen until evaluation. The straws containing 0.25 ml semen were thawed at water bath temperatures at (i) 37ºC for 30s and (ii) 60ºC for 6 s. Following the freeze-thawing process, the effects of time exposure and thawing temperature on the kinematic features (CASA), viability, plasma membrane integrity (HOS test), morphological abnormalities, malondialdehyde (MDA) concentration, antioxidant activity (GPx, SOD) and total antioxidant capacity (TAC) were evaluated. The experiment was conducted as a completely randomized and the statistical model includes the effect of temperature and thawing time. The data were analyzed by the general linear model (GLM) procedure and statistical differences between the various group means were determined by Tukey's test. Significant differences were reported at the level of (P<0/05). The results showed that sperm motility parameters such as PM, VSL, VCL were improved at 37°C, but this increase was not statistically significant. The viability and plasma membrane integrity was improved at 37°C for 30 s compared 60°C for 6 s, but it was no significant. Also, total abnormality did not improve at high thawing rates than low rates. In addition, the results of the comparison of lipid peroxidation (MDA), glutathione peroxidase (GPX), superoxide dismutase (SOD) and total antioxidant capacity (TAC) were no significant at two thawing rates. According to the results obtained from thawing methods, the thawing at 60°C for 6s cannot be a suitable alternative for semen thawing at 37°C for 30 seconds.

 

One of the pivotal technology for genetic resorviors preservation is the freezing of semen. As freezing causes a reduction in sperm fertility, adding some components to semen to preserve its ferility would be important. Since beginning the time of artificial insemination technique, different diluents have been used to preservation semen in liquid and frozen condition. Therefore, the goal of this stady was to investigate the effect of adding different levels of raffinose and milk, Tris-chicken egg yolk and Tris-soybean lecithin extenders on ovine semen characteristics after freezing and thawing.

Samples were collected from four mature Dalagh rams and extended by different extenders and then raffinose was added. Semen samples were aspirated into 0.5 ml straws and cooled to 4°C within 150 min and then frozen in liquid nitrogen Frozen straws were transferred to a tank containing liquid nitrogen. After thawing spermatozoa quality parameters including percentage of sperm motility, viability, membrane integrity and sperm normality were evaluated. This study was performed in a 4×3 factorial experiment with a completely randomized arrangement. Treatments were four levels of raffinose (0, 60, 70 and 80 mmol) and also three kinds of extenders (milk, tris-egg yolk and tris-soy lecithin). The obtained data from this study were analyzed by ANOVA procedure of Statistical Analysis System SAS (version 9.1). Comparison of data means were performed by Tukey test at the level of %1 error.

Results showed that adding raffinose had a significant effect on sperm viability and mobility (P<0.01), but did not significantly affect on sperm memberane integrity and normal morphology percentages. Effect of extender on percentages of motility, viability, membrane integrity and normal morphology of sperms was significant (P<0.01). The interaction between raffinose levels and extenders on percentages of motility, membrane integrity and normal morphology of sperms was significant while it was not for viability percentage. The greatest sperm mobility (35.00±2.09%) was in tris-egg yolk extender containing 60 mmol raffinose while that greatest sperm viabilty (74.40±1.88%) was in tris-egg yolk extender containing 80 mmol raffinose but also the most percentages of membrane integrity (66.40±2.60%) was in Tris-chicken egg yolk containing 0 mM raffinose. The greatest sperm normal morphology (74.80±2.82%) was observed in tris-soy lecithin extender containing 60 mmol raffinose.

Findings of the study showed that sperm characteristics including mobility and normal morphology percentages in level 60ml raffinose, membrane integrity percentages in level 0ml raffinose wihle for viability percentage were better preserved in 80ml level. In the other hand, tris-egg yolk extender had more prominant effect on preservation of sperm characteristics.

The highest damage to the sperm is caused by oxidative stress due to the production of reactive oxygen species (ROS). Semen cryopreservation causes some structural, biochemical and functional changes, which leads to various problems in sperm transport, survival and fertility rate in domestic animals. Also, sperm metabolism produces ROS, which is potentially harmful to the sperm plasma membrane integrity loss of motility .High concentrations of ROS have negative effects on sperm quality and increased degradation of DNA, lipid peroxidation and oxidative stress which inhibits sperm motility and changes in sperm infrastructure and finally the reduction of fertility.
Seminal plasma contains enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) which have an important role in the inhibition of the deleterious effects of ROS. Lipid peroxidation may be due to lack of coordination between SOD, GPX, and CAT in seminal plasma or deficiency of total antioxidant capacity of the cell. Ellagic acid is a polyphenol compound that can be found in green tea and other natural resources such as pomegranate, strawberry, raspberry, walnut and eucalyptus bark. Ellagic acid showed antioxidant and anti-apoptotic effects, it can delay or prevent cellular oxidation; ultimately reduce oxidative stress.Ellagic acid increases the activity of enzymes SOD, CAT and GPx by preventing free radical attack to cells. This research was conducted to evaluate the antioxidant effect of different levels of Elligic acid on microscopic, biochemical parameters, antioxidant enzyme activities and total antioxidant capacity of ram semen after freezing-thawing process.
Five Ghezel rams were used. Semen samples were collected twice a week using artificial vagina. In order to remove individual effects, the semen samples were pooled together. Different levels of ellagic acid (0.25, 0.5, 1, 1.5 mM) were added in diluent of tris-lecithin based. After processing and freezing, the samples were stored in liquid nitrogen until the time of evaluation. After thawing of semen samples, sperm motility parameters were evaluated using CASA system, viability by with Eosin-nigrosin staining, membrane integrity with a solution of hypo-osmotic, sperm abnormalities using a solution of Hancock, lipid peroxidation by measuring malondialdehyde and the seminal plasma antioxidant enzymes of glutathione peroxidase, superoxide dismutase and total antioxidant capacity using the RANDOX Laboratories kit. The data were analyzed with SAS (9.1.3) software using GLM procedures.
The results showed that the levels of 0.25, 0.5, 1 and 1.5 mM ellagic acid improved survival and total motility parameters (P The findings of this study showed that the diluent containing 0.5 mM ellagic acid significantly improved sperm parameters compared to other levels, after freezing-thawing process.

The sheep artificial insemination with frozen-thawed semen have a low fertility rate because cryopreservation of ram semen is difficult.
The aim of this study was to investigate the effect of supplementation of diluent with different trehalose concentrations on during of storage cryopreservation of different rams’ semen in reproductive season.
Ejaculate samples were collected from six adult rams. Samples immediately were transported to the laboratory. After a primary evaluation, semen samples were diluted, with a Tris-based extender complemented with 50, 75, 100 mM trehalose and an extender containing no sugar as a control group. Semen samples were aspirated into 0.25 ml straws, cooled to 5°C and after frozen finally stored in liquid nitrogen. The frozen straws were evaluated for motility, progressive motility, percentage of live sperm and morphology for 15 days.
Achieved results showed that the highest percentage of alive sperms belonged to 75 mM trehalose and control group had the lowest percantage of alive sperms. The highest percentage of motility and progressive motility were recorded in concentrations of 75 mM and 100 mM, while the control group had the lowest percentage of motile sperm and progressive motility, on the other hand, no significant differences were observed in the percentages of abnormality the extender containing of trehalose and control group.
The highest percentage of alive sperms recorded for the Ghezel rams. Percentage of motility, progressive motility and abnormality in Ghezel-Merinos rams were better than other groups. The results of this study showed trehalozse improved cryopreservation of ram semen.

The cryopreservation of spermatozoa has provided special opportunities for the preservation of genetic resources and improving breed programs by the artificial insemination technique (Holt, 1996). Sperm cryopreservation stimulates intracellular ice crystals formation, increasing osmotic and chilling injury that causes sperm cell damage (Isachenko et al. 2003). Freezing and thawing processes impose physical and chemical insults on the sperm membrane that decrease sperm viability and fertilizing ability (Alvarez and Storey, 1992). Both damages are associated with excessive generation of reactive oxygen species (ROS) and peroxidation of the phospholipids in the membrane (Wang et al. 1997; Lasso et al. 1994). High concentrations of ROS have a negative effect on sperm quality and increased degradation of DNA, lipid peroxidation and oxidative stress which inhibits sperm motility and changes the structure of sperm and finally the reduces the fertility (Aitken et al., 1997; Agarwal and Saleh, 2002; Khosrowbeygi and Zarghami, 2007; Zalata et al., 1995). Seminal plasma contains enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) which have an important role in the inhibition of the deleterious effects of ROS. Lipid peroxidation may be done due to lack of coordination between SOD, GPX, and CAT in seminal plasma or deficiency of total antioxidant capacity of the cell (Tavilani et al., 2008). Ascorbic acid is the main water-soluble antioxidant which acts as a scavenger for a whole range of reactive oxygen species. Ascorbic acid acts as a strong electron donor reacts with superoxide, peroxide and hydroxyl to form dehydroascorbic acid. Ascorbic acid protects sperm DNA against damage caused by H2O2 radical and reduces the amount of nitrite. This study was conducted to study the effects of adding ascorbic acid on sperm quality, plasma lipid peroxidation and antioxidant enzyme activities of ram semen after freeze- thawing process.
Material and Five sexually mature Ghezel rams (3 to 4 years of age) were used. Semen samples were collected every three days using an artificial vagina. In order to eliminate the individual differences, ejaculates containing sperm with >80% progressive motility, volume of 0.75 to 2 mL, sperm concentrations greater than 3 × 109 sperm/mL and sperm abnormalities of less than 10%, were pooled. Different levels of Ascorbic acid (0, 0.5, 1, 1.5 and 2 mg mL-1) were added in tris-egg yolk based diluent. After processing and freezing, the samples were stored in liquid nitrogen until the time of evaluation. After thawing of semen samples, Sperm motility characteristics were analyzed using computer-assisted sperm analysis. The sperm viability was determined by means of the nigrosin–eosin staining method. The hypo-osmotic swelling test (HOS-test) was used to evaluate functional sperm plasma membrane integrity after freeze-thawing. Sperm abnormalities were assessed using Hancock solution. Lipid peroxidation was measured with determining malondialdehyde and the seminal plasma antioxidant enzymes of glutathione peroxidase, superoxide dismutase and total antioxidant capacity using the RANDOX Laboratories kit. Statistical analyses were performed using SAS software (9.1.3) software using GLM procedures. The least square means were calculated to determine the differences between the experimental treatments for the post-thaw evaluation times.
The results showed that the 1 and 1.5 mg/mL ascorbic acid significantly improved the total motility (TM), progressive motility (PM), curvilinear velocity (VCL) compared to the control group (P

Semen collection and sperm evaluation are essential for successful artificial insemination. This study was conducted on 4 rams. Average age of rams was 2-3 years old (2 Ghezel Merino and 2 Merino Moghani). The aim of the present study was to evaluate seasonal variation in semen characteristics. After rams were trained to serve the artificial insemination، semen samples were collected weekly from august 2011 to June 2012. Semen ejaculates were evaluated for volume، color، non- microscopic mass motility، wave motion، pH، sperm progressive motility، percentage of live and dead sperm and concentration. Regarding to semen production، it was found that semen collecting time affected in all seminal characteristics during the breeding and non-breeding seasons. Differences in genetic effect were observed significantly on almost seminal characteristics (P<0. 05) except volume and pH during in breeding season. Merino Moghani performance was better than Ghezel Merinos during breeding season. Ghezel Merino ram only had reproductive activity during non-breeding season.

Experiment was conducted to study the effect of different antibiotics on sperm quality of ram by a completely randomized block design using 23 factorial arrangement with 2 block and 4 observations in each experimental units. Factors include three antibiotics named Gentamycin (G), Lincomycin (L) and Ampicillin (A) that were used at two different levels including zero and, respectively 5, 10 and 2.5 μg / ml of diluents. Tris-based and skimmed milk-based diluents were considered as block1 and block2 respectively. Semen was collected from four rams in 8 times. Samples were aggregated and divided into eight equal parts. The different levels of antibiotics were added to each part. Samples temperature was reduced at a rate of 0.25° C/min t 5° C and was stored at this temperature for 72 hours. Sperms evaluations were performed at 0, 24, 48 and 72 h after storage. The interactions between antibiotics on the progressive mobility, plasma membrane integrity and viability of sperm were significant (P<0.05).After 0,24,48 and 72h of storage, progressive motility(78.19, 66.26% and 54.52%), plasma membrane integrity(85.12%,75.12% and 62.62%) and viability of sperm(86.12% 78.38% and 70.62%) in a0g0l10 (Lincomycin 10μg / ml of diluents) were significantly (P<0.05) higher than other treatments except a0g5l0 (Gentamycin 5μg / ml of diluents) at 24, 48 and 72 h after storage. However the characteristics of a0g0l10were significantly higher than a0g5l0 at time zero. From this study we concluded that using Lincomycin 10μg / ml had the most effect on quality of spermatozoa during storage at 5° C.