Camel Spermatozoa Research Articles

Use of a sperm-Hyaluronan binding assay for evaluation of sperm quality in dromedary camels

The objective of this study was to assess the ability of camel spermatozoa to bind in the Hyaluronan Binding Assay (HBA), to determine if conventional sperm quality parameters, in vitro fertilization capacity, and precursor of A-Kinase Anchoring Protein 4 (proAKAP4) values correlate with HBA results. The potential to predict post-thaw fertilization performance from HBA for fresh dromedary camel sperm was also evaluated. Semen samples were collected and assessed both fresh and post thawing, at 0 h and 1.5 h. Conventional semen analysis, HBA, and a proAKAP4 biomarker-test were used to validate sperm quality. A heterologous sperm penetration assay using zona pellucida-free goat oocytes was used to assess in vitro sperm fertilizing capacity. The results showed that dromedary camel spermatozoa bound to hyaluronan with no correlation between results from fresh samples and after thawing. Furthermore, the proAKAP4 test results showed a negative correlation with HBA at 0 h after thawing (r = - 0.62; P = 0.03). In the conventional analysis, only progressive motility (r = 0.65; P = 0.02) and straightness correlated with HBA for fresh semen (r = 0.69; P = 0.01). In the sperm penetration assay, a moderate but non-significant correlation was identified between fresh sperm HBA and penetration (r = 0.52; P = 0.07). In conclusion, results suggested that HBA can be used to assess camel sperm properties, but further investigation is needed to understand its correlation with other sperm quality parameters. The HBA score from fresh dromedary camel sperm was unable to predict post-thaw fertilization performance.

The Effect of Cushioned Centrifugation, with and without Enzymatic Reduction of Viscosity, on the Motility Pattern and Kinematic Parameters of Dromedary Camel Bull Spermatozoa.

In order to contribute to the development of semen processing procedures in camelids, the aims of the present study were to evaluate (i) the effect of 35% seminal plasma incubation on dromedary camel epididymal sperm motility and kinematic parameters, (ii) the effects of centrifugation, with cushion fluid and enzymatic reduction of viscosity (Papain + E64) during ejaculate processing, on the motility and kinematic parameters of dromedary camel ejaculates. The incubation with seminal plasma significantly reduced the percentage of progressively motile spermatozoa as well as the proportion of medium progressive spermatozoa whilst increasing the percentage of non-progressive spermatozoa. The centrifugation procedure improved the sperms' kinematic parameters, and the highest values were observed for samples centrifugated with cushion fluid. The samples treated with Papain + E64 showed a significant increase in both total and medium progressive spermatozoa, along with a reduction of non-progressive spermatozoa (p < 0.05). The results of this investigation show that a simple, cheap, and effective procedure, such as cushioned centrifugation, could improve the motility patterns of dromedary camel spermatozoa; in combination with enzymatic reduction of viscosity, this method leads to the best results in terms of recovery rates and sperms' kinematic parameters.

Immunolocalization and expression of Siglec5 protein in the male reproductive tract of dromedary camel during rutting season.

Lectins are carbohydrate-binding proteins that are highly selective for sugar groups on other molecules. Siglec5 is a cell-surface lectin that belongs to the sialic acid-binding Ig-like lectins (Siglecs) and acts as a suppressor of immune responses. In this study, immunohistochemistry, western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of Siglec5 in the male reproductive tract of dromedary camels during the rutting season. Siglec5 displayed strong immunostaining in the cranial and caudal testicular regions and moderate immunostaining in the rete testis. Different parts of the epididymis showed varying immunoreactions to Siglec5. The spermatozoa in the testes and epididymis also showed positive immunostaining for Siglec5, whereas, the vas deferens showed negative immunostaining for the protein. The results obtained by western blotting confirmed the immunohistochemical detection of the protein in the testicular and epididymal tissues. The results of qRT-PCR showed that Siglec mRNA was expressed differently in each part of the testis and epididymis; the highest levels of expression were observed in the caudal part of the testis and in the head of the epididymis. In conclusion, the present study revealed that Siglec5 is mainly located in the testis and epididymis, where sperm production and maturation occur. Therefore, this protein may play an essential role in the development, maturation and protection of camel sperm.

Sperm freezability is neither associated with the expression of aquaporin 3 nor sperm head dimensions in dromedary camel (Camelus dromedarius)

The expression of aquaglyceroporin 3 (AQP-3) has been demonstrated in the spermatozoa of several mammalian species and its role has been associated with cryotolerance. Post-thaw sperm quality from individual dromedary males with different response to freezing-thawing process was evaluated through sperm head morphometry. In order to understand the cellular mechanisms affected by cryoinjury we have explored the presence and distribution of sperm AQP-3 using western blotting and immunocytochemistry. WB showed different intensity of the specific signal bands at 28 kDa. Immunofluorescence assessments allowed us to identify five different and clear AQP-3 distribution patterns of labelling in the sperm plasma membrane; acrosome, post-acrosome, mid-piece, and principal and final tail. Although expression of AQP-3 varied among male ejaculates, the individual sperm response to freeze-thawing was not associated with AQP-3 expression. Thus, AQP3 expressions do not seem like a reliable predictor of sperm response to freeze-thawing process in this species. This work is the first to describe the morphometric characteristics of the heads of dromedary spermatozoa. No correlation was found between sperm head dimensions and sperm quality variables after freeze-thawing suggesting that dromedary camel sperm head morphometry is also not a reliable predictor of cryosurvival.

Preservability and conception of chilled and cryopreserved semen with Triladyl egg yolk extender in dromedary camels (Camelus dromedarius)

Artificial insemination (AI) technology has not shown much advancements in camels, attributable to various difficulties of semen preservation and insemination in the species. The present study intended to explore the preservability of camel semen under chilled and frozen states, improve proficiency of AI steps and assess conception to AI. Over the two years of study, 383 ejaculates collected from five adult male camels were preserved in Triladyl egg yolk extender using refrigeration or liquid nitrogen and used for AI trials in camels subjected to induction of ovulation. Under chilled storage, even though few samples retained satisfactory motility even beyond 96 h, a majority of the samples suffered significant drop in motility within 24 h. Out of 239 and 739 freezing trials (FT) respectively in the first and second seasons, 18.83% and 23.00% FT achieved a post-thaw motility (PTM) of at least 40%. Insemination studies showed progressive decrease in conception rate with the duration of chilled storage since fresh extended and 24 h chilled semen samples produced 32% and 3.7% conception respectively. Cryopreserved semen achieved two pregnancies (1.82%) out of 110 inseminations in the second season. It is concluded that camel spermatozoa suffers rapid depletion of conception chance upon preservation and underlying reasons needs to be investigated. However, the achievement of two pregnancies indicates the possibility of conception and the scope for cryopreservation based AI technology in dromedary camels.

Identification of proAKAP4 concentration variations in dromedary sperm and their correlation with monthly semen parameters.

ProAKAP4 is synthetized as a precursor polypeptide that must be converted into mature AKAP4 in living spermatozoa and is considered as a functional marker of spermatozoa. The gene is well-conserved in mammals although uncharacterized in Camelidae. In the present study, we investigate the expression metabolism of proAKAP4 and AKAP4 proteins and evaluate their seasonal dynamics relative to semen quality in dromedary camels. Semen parameters including volume and viscosity and characteristics of sperm including concentration, total production, total and progressive motility, vitality, acrosome integrity and morphological abnormalities were assessed in semen samples collected weekly from six camels during the rutting season, from November to April. Only total sperm production varied, peaking in January. Both the precursor proAKAP4 and AKAP4 proteins were investigated and shown to express biochemical properties similar to those described in other mammals. ProAKAP4 concentrations expressed in ng/10 million spermatozoa as assayed using a specific ELISA showed a strong positive correlation with ejaculate volume (P = 0.045), viscosity (P < 0.001) and sperm total motility (P = 0.049). Furthermore, their concentrations exhibited clear seasonal variations in camel semen. In conclusion, the assessment of proAKAP4 concentrations in camel sperm provides a novel parameter to assess sperm quality. Further studies should be performed to investigate proAKAP4 concentrations relative to fertility in Camelidae that may help to define the right time for mating and semen collection and increase the success of breeding programs.Lay summaryBreeding related to the seasons/time of year in the camel has been reported in several studies. A better knowledge of semen quality during the breeding season would assist in determining the best period for mating in camels. However, conventional sperm parameters are held to be unsatisfactory because they cannot predict breeding potential. ProAKAP4 a sperm-specific protein has been described as a functional marker of sperm and a key fertility marker in several species but has not been described in camels. Motility or membrane integrity parameters of semen collected throughout the breeding season and also the presence of proAKAP4 protein were investigated. ProAKAP4 was identified for the first time in camels and their concentrations exhibited clear seasonal variations in camel semen showing strong correlations with ejaculate volume and total motility and viscosity. Further studies should be performed to investigate proAKAP4 concentrations relative to fertility in camels to define the right time for mating and increase the success of breeding programs.

Interaction among extenders, cryoprotectants and Orvus Es Paste supplementation and freezing rate for sperm cryopreservation in the dromedary camel.

This study evaluated the effects of freezing extenders, cryoprotectants and their concentrations, presence of Orvus Es Paste and freezing rates for cryopreserving dromedary camel sperm. Semen (five males; 2 ejaculates/male) was frozen in one of the following extenders (Green Buffer® or INRA96® ), cryoprotectants (3 and 6% glycerol or ethylene glycol), with or without Orvus Es Paste and freezing at two different heights (1 and 4cm) above liquid nitrogen. Sperm motility recovery parameters were evaluated post-thaw (0 and 1hr), vitality and acrosome integrity (0hr). Green Buffer showed higher total motility recoveries (p<.001). Higher percentage of cryoprotectant improved both total and progressive motility at 0hr (p<.001; p=.003) and 1hr (p<.001; p=.005). Acrosome integrity at thawing increased in the presence of ethylene glycol (p<.001) and Orvus Es Paste (p=.001). Kinematics were affected by extender, cryoprotectant concentration and Orvus Es Paste at 0 and 1hr, and type of cryoprotectant only influenced them at 0h. Our findings showed strong interactions among type of cryoprotectant and concentration, and extender and Orvus Es Paste. Generally, combining Green Buffer, 3%-6% ethylene glycol or 6% glycerol without Orvus Es Paste, regardless of the freezing rates, yielded the highest post-thaw parameters for camel sperm.

Effect of melatonin supplementation during IVM of dromedary camel oocytes (Camelus dromedarius) on their maturation, fertilization, and developmental rates in vitro

The positive impact of melatonin on in vitro embryo production (IVEP) has been reported in many domestic species; however, no studies have been carried out in camelids. We aimed to evaluate the effects of melatonin supplementation in maturation media on in vitro maturation, fertilization, and preimplantation embryo development of dromedary camel oocytes (experiment 1). We also evaluated the concentrations of total antioxidant capacity (TAC), and malondialdehyde (MDA) in the IVM spent medium in relation to melatonin supplementation. Cumulus oocyte complexes (COCs) were cultured in in vitro maturation media (IVM) supplemented with either 0.0, 25.0, 50.0 or 75.0 μM of melatonin for 30 h. Matured oocytes were then fertilized in vitro with epididymal camel spermatozoa. Following IVF, the resulting embryos were cultured in vitro for seven days. The percentage of maturation, fertilization, cleavage, and embryo developmental rates (morula and blastocyst) was recorded (experiment 1). TAC and MDA levels in the IVM spent maturation media were also evaluated at 30 h post-IVM (experiment 2). The results showed that supplementation of IVM media with 25 μM melatonin significantly improved oocyte nuclear maturation, fertilization (18 h post-insemination; pi), cleavage (day 3 pi), morula (day 5 pi) and blastocyst (day 7 pi) rates as compared with the controls and other melatonin-supplemented groups. Furthermore, the TAC in the IVM spent media was significantly increased (P < 0.05) in 25 μM melatonin supplemented groups than those supplemented with 0.0, 50.0, 75.0 μM melatonin. However, the concentration of MDA was significantly lower (P < 0.05) in IVM media supplemented with 25.0 μM of melatonin when compared with the control and other treatment groups. In conclusion, supplementation of IVM medium with 25 μM of melatonin could enhance the in vitro developmental capacity of dromedary camel oocytes.

Establishment of a Cyclodextrin-Based Medium for Cryopreservation of Camel Sperm (Camelus dromedaries).

Establishment of a Cyclodextrin-Based Medium for Cryopreservation of Camel Sperm (Camelus dromedaries).

Effects of vitamin C, vitamin E, selenium, zinc, or their nanoparticles on camel epididymal spermatozoa stored at 4°C.

This study determined the effects of antioxidant supplementation and storage time at cool temperatures on the characteristics of epididymal camel spermatozoa. Camel testes were collected at the abattoir after animal slaughtering and kept at 4°C during transportation and until processing (max 6h). Spermatozoa were retrieved and diluted with SHOTOR extender, split in aliquots, supplemented with the following antioxidants: 200μm/mL vitamin E, 1.0g/L vitamin C, 1μg/mL selenium nanoparticles, 50μg/mL zinc nanoparticles, 2μg/mL sodium selenite, and 100μg/mL zinc sulfate, and stored at 4°C for 2, 48, 96, and 144h. The storage time significantly affected (P < 0.05) the sperms' motility and livability, the sperms' membrane integrity, and the percentages of cytoplasmic droplets as well as the percentage of morphologically normal spermatozoa. Epididymal sperm characteristics (progressive motility, livability, membrane integrity, and abnormalities) were significantly improved (P < 0.05) when the spermatozoa were diluted with antioxidants as compared with the control group, and the best additives were identified as nano-selenium, sodium selenite, nano-zinc, and zinc sulfate. In conclusion, adding nano-sized minerals or inorganic trace elements and vitamins maintained the progressive motility, livability, and membrane integrity, and decreased abnormalities and cytoplasmic droplet percentages of epididymal camel spermatozoa stored at 4°C up to 144h.

Effect of Green Laser Irradiation on Epididymal Camel Spermatozoa Quality Stored At 5°C

Total number of forty testes from twenty Sudani camels (Camelus dromedarius) were used in the present study (>5-10 years old and 500-600 kg body weight). The experimental work was executed to define the effect of green laser irradiation with short-wavelength 532 nm and continuous wave from a diode laser light with a total output power of 3 mW on epididymal camel spermatozoa quality at different exposure times of 0 (control, non-irradiated), 2, 4, 6, 8, and 10 min. Following irradiation, the percentages of motile spermatozoa, storagability, viability, and acrosomal damage were assessed of the epididymal camel spermatozoa stored at 5°C for 4 days. Epididymal spermatozoa was diluted with lactose-yolk-citrate (LYC) extender. The obtained results showed that the highest (P<0.05) value of the percentages of motile and storagability of spermatozoa was recorded with spermatozoa exposed to 6 min of laser irradiation and the lowest (P<0.05) value was recorded with the control group. Otherwise, the highest (P<0.05) value of the percentages of dead and acrosomal damage of spermatozoa was recorded with spermatozoa exposed to 10 min and the lowest (P<0.05) value was recorded with 2 min. The advancement of storage time at 5°C decreased (P<0.05) the percentages of motile and storagability of spermatozoa, while increased (P<0.05) the percentages of dead and acrosomal damage of spermatozoa during storage at 5°C for 4 days. Consequently, enhancing the artificial insemination program can be achieved using the laser irradiation which is considered a cost-effective technique for improving semen quality. The profitable effects of laser irradiation on epididymal camel spermatozoa quality raised the motile spermatozoa, storagability, livability, acrosomal integrity which consider an indicator to improve mitochondrial function which extends the survival of spermatozoa

Localization and expression of ADAM2 in the dromedary camel testis, epididymis and sperm during rutting season.

ADAM2 (fertilin β) is a sperm surface protein reported in several mammalian species. However, the presence of ADAM2 in the male reproductive system and sperm of the camel is not well known. The present study was to clarify the localization and expression of ADAM2 in the dromedary camel testis, epididymis and spermatozoa during rutting season using immunohistochemistry (IHC) and the quantitative real-time polymerase chain reaction (qPCR). Tissue samples were obtained from the testis (proximal and distal) and epididymis (caput, corpus, and cauda) from eight mature male camels. Epididymal and ejaculated sperms were collected from four other fertile camels. IHC analysis clearly showed the localization of ADAM2 protein in the spermatocytes and the round and elongated spermatids of the testis, in the epithelial cells along the epididymis tract, on the posterior head of the sperm within the cauda epididymis, and on the acrosomal cap of both the epididymal and ejaculated sperm. The expression of camel ADAM2 mRNA was significantly higher (P < 0.05) in the testis when compared with the epididymis. These findings may suggest an important role of ADAM2 in the fertility of male dromedary camels.

Purification of cryopreserved camel spermatozoa following protease-based semen liquefaction by lectin-functionalized DNA-defrag magnetic nanoparticles.

Although incorporating proteases into sperm medium is considered the most effective procedure to eliminate camel semen viscosity, it drastically affects viability, morpho-functional properties and, hence, fertilization potential of spermatozoa. The present work aimed at evaluating adequacy of employing magnetic nanoparticles-based sperm purification technique for eluting impaired and apoptotic camel spermatozoa from cryopreserved semen doses following protease-based semen liquefaction. Thirty cryopreserved semen doses (50 x 106 sperm/straw) representing the following liquefaction treatments: control (untreated), 0.1mg/ml papain or 5 U/ml bromelain were used (n=10 straws per treatment). Immediately after thawing (38°C for 40s), sperm concentration of each straw within treatment was readjusted to 15 x 106 sperm/mL by dilution in PBS (37°C). Sperm physical and cytological properties were then assessed (non-purified semen). Thereafter, each specimen was subjected to lectin-functionalized DNA-defrag magnetic nanoparticles sperm purification, and the same sperm traits were re-evaluated after undergoing purification (purified semen). Sperm DNA fragmentation level within each group, prior to and after magnetic nano-purification, was also determined by fluorescent imaging. The results showed a dramatic improvement (p<.05) in post-thaw motility (%), viability (%), normal sperm (%), intact acrosome (%) and HOST-reacted (%) spermatozoa in protease-liquefied semen following sperm magnetic nano-purification. Additionally, the highest (p<.05) DNA fragmentation level was recorded in all cryopreserved semen groups prior to purification, whereas the lowest (p<.05) was observed in the protease-treated specimens after magnetic nano-purification. These results indicate that protease-based semen liquefaction prior to cryopreservation in conjunction with magnetic nano-purification post-thawing holds potential for reducing the proportion of damaged and dead spermatozoa, hence improving camel sperm fertilization competence.

Preservation of the spermatozoa of the dromedary camel (Camelus dromedarius) by chilling and freezing: The effects of cooling time, extender composition and catalase supplementation

This study sought to determine the characteristics of dromedary camel sperm following 24 h chilling and cryopreservation, testing two different buffers and cryoprotectants and the presence of catalase (500 IU/mL). Ejaculates were liquefied in Tris-Citric acid-Fructose buffer, and centrifuged through a colloid. For Experiment 1 (n = 5) sperm were cooled 24 h in Green Buffer or INRA-96® containing 0 or 3% glycerol or ethylene glycol. Experiment 2 (n = 5) used the same six treatments to evaluate sperm cryopreserved after 24 h cooling. A test of fertility was run (n = 12 recipients) with split ejaculates of fresh semen cooled 24 h in Green Buffer with and without glycerol. Experiment 3 (n = 7) cryopreserved sperm cooled 2 and 24 h in Green Buffer without cryoprotectant and with and without catalase. Sperm parameters measured before and after treatments included motility, viability and acrosome integrity. Experiment 1 showed no reduction in all sperm parameters after 24 h and no differences between buffers or presence or not of either cryoprotectant. Experiment 2 showed Green Buffer to be better than INRA for supporting sperm frozen after 24 h cooling while, for both buffers, there were few differences in sperm parameters if cryoprotectant was present or absent. Pregnancies were confirmed in 4/6 animals (67%) while no recipients receiving sperm chilled with glycerol were pregnant. In Experiment 3, catalase-supplemented sperm had maintained better motility 2 h post thaw; there were no differences between 2 or 24 h cooled sperm parameters for presence or absence of catalase. There was neither advantage nor disadvantage to coooling sperm 24 h prior to cryopreservation. We concluded that dromedary sperm can be chilled (24 h) and then either inseminated or cryopreserved. While glycerol presence in Green Buffer during chilling did not interfere with cryosurvival it may be toxic to the fertility of fresh chilled sperm. Catalase supplementation during cooling helps maintain sperm motility post thaw.

TESTICULAR CHANGES AND SPERM CHARACTERISTICS IN THE DIFFERENT DROMEDARY CAMEL BREEDS DURING THE BREEDING AND NON-BREEDING SEASONS

Sixty- four male dromedary camel testes from different breeds (Fellahi, Maghrebi and Sudani) during the breeding and non –breeding seasons were used. The experimental work aimed to define the effect of breed and seasons on testicular measurements and sperm characteristics. The penetrating ability of spermatozoa into she-camel cervical mucus was also assessed. The obtained results revealed that, testes weight (g), testicular volume (cm3), scrotal circumference (cm) and testes tone firmer score were significantly (P<0.05) higher during the breeding than during the non- breeding season, while insignificant differences between Fellahi and Maghrebi than Sudani camels were detected. Percentage of sperm motility and sperm-cell concentration (x106/ml) were significantly (P<0.05) higher, while the percentages of dead spermatozoa, abnormal spermatozoa, acrosomal damage and chromatin damage of spermatozoa were significantly (P<0.05) lower in the breeding than in the non-breeding season in Fellahi and Maghrebi camels as compared with Sudani ones. Penetrating ability of spermatozoa into she-camel cervical mucus was significantly (P<0.05) better during the breeding than non- breeding season in the different breeds (Fellahi, Maghrebi and Sudanese camels). The penetrating ability of spermatozoa into she-camel cervical mucus was not significant in the various breeds (Fellahi, Maghrebi and Sudanese camels). Moreover, the prolongation of incubation time at 37oC for 4 hours significantly (P<0.05) decreased the penetrating ability of spermatozoa into she-camel cervical mucus either in the breeding or the non-breeding season with the different dromedary camel breeds. In conclusion, sperm characteristics and ability of Fellahi and Maghrebi camel spermatozoa to penetrate cervical mucus during the breeding season showed better performance than Sudani camel spermatozoa.

Optimization of sperm freezability in Bactrian camel using various dilution rates and equilibration times

The effect of different dilution rates and equilibration times on the cryopreservation of Bactrian camel spermatozoa was evaluated in the current study. Semen samples from four healthy adult males were collected, processed and pooled. They were then subjected to a completely randomized 4×2 factorial design including four dilution rates (DR; 1:1, 1:2, 1:4 or 1:8; v:v with SHOTOR diluent) and two equilibration times (ET; 1 or 2 h at 5ºC). After freezing and thawing, sperm kinematic parameters as well as viability, plasma membrane integrity, abnormality and seminal malondialdehyde level were assessed. According to the results, four-fold diluted samples recorded significantly higher values (P < 0.05) for sperm total (39.58 vs 31.83 and 33.33,%) and progressive motility (19.50 vs 14.00 and 14.25,%), viability (55.37 vs 43.50 and 48.75,%) and plasma membrane integrity (46.75 vs 37.25 and 37.37,%) than those of both less (1:1) and high (1:8) concentrated samples, respectively. By contrast, the percentage of abnormal spermatozoa and the concentration of seminal malondialdehyde were comparable among all treated groups. Moreover, ET revealed that 1 h equilibration had significantly higher sperm motility (37.04 vs 33.33%), linearity (42.29 vs 32.26%), beat cross-frequency (13.15 vs 8.70 Hz), plasma membrane integrity (42.25 vs 39.75%) and viability (51.37 vs 48.12%) compared with 2 h of ET (P < 0.05). Taken together, a four-fold dilution along with 1 h equilibration can be an optimal procedure to cryopreserve Bactrian camel sperm.

Individual male dependent improvement in post-thaw dromedary camel sperm quality after addition of catalase

Cryopreservation is stressful to sperm cells inducing an increase in the production of reactive oxygen species and subsequently reducing post-thaw sperm quality. With the present study, there was evaluation of the protective effects of two antioxidants, epigallocatechin (1 mM) and catalase (500 IU/ml), added at thawing, as well as inter-individual variation on quality of cryopreserved dromedary camel spermatozoa. Semen was collected from six males and sperm, selected using single layer centrifugation, were cryopreserved. Post-thaw sperm quality was evaluated by assessing motility variables, viability and acrosome integrity then sperm were co-incubated with or without antioxidant (control) and further assessed at 1.5 and 3 h of the incubation period. Oxidative damage was measured colorimetrically for malondialdehyde production at 3 h of the incubation period. With the use of epigallocatechin there were not promising results, however, with use of catalase there were greater total and progressive motility, and values for some kinematic variables (P<0.05) at both incubation time points, although there were some differences among males. There was no overall effect of antioxidant based on production of malonaldehyde. The capacity of thawed sperm to fertilize, with and without addition of catalase at thawing, was studied using artificial insemination (n = 10 per treatment) with no differences between treatments (10% for both). It is concluded that catalase supplementations to semen extender prolong sperm survival, however, there is no improvement of in vivo fertilization as a result of this supplementation. There was an obvious male effect, necessitating further studies to understand the mechanisms of action of catalase.

Liquid storage of dromedary camel semen in different extenders

This study was conducted to assess the effects of commercial extenders and storage temperature on dromedary camel sperm quality during liquid preservation. In Experiment 1, ejaculates (n = five males; replicated seven times) were split and diluted with synthetic (OPTIXcell, EquiPlus, INRA96, Bioxcell or AndroMed; Experiment 1a) or egg-yolk based (Biladyl, Green buffer or Triladyl; Experiment 1b) extenders and stored for 48 h at 4 °C. In Experiment 2, split ejaculates (n = five males; replicated six times) were used to directly compare Green buffer, OPTIXcell and Triladyl extenders over 48 h of storage at 4 °C. Ejaculates collected in Experiment 3 (n = five males; replicated five times) were diluted with Green buffer or Triladyl before chilled storage for 48 h at 4 or 15 °C. Sperm kinematics, viability and acrosome integrity were assessed during liquid storage. In Experiment 1a, there was the greatest total sperm motility (TM) in the OPTIXcell group following 24 and 48 h of storage, while in Experiment 1b, there was the greatest TM after 48 h of storage with Triladyl and Green buffer. In Experiment 2, there were greater TM and viable acrosome intact spermatozoa in the Triladyl and Green buffer than with OPTIXcell group. In Experiment 3, there was a greater TM in the Triladyl than Green buffer group at 24 and 48 h of storage regardless of storage temperature (which had no effect on sperm quality). In conclusion, camel sperm have greater viability when preserved in liquid form for 48 h following dilution with Triladyl and storage at either 4 or 15 °C.

INFLUENCE OF GLUTATHIONE ADDITION TO THE EXTENDER ON THE COOLED CAMEL SEMEN QUALITY

Semen was collected, evaluated and extended with two extenders (Lactose-yolk-citrate: LYC and Tris-yolk-fructose: TYF .The final extension rate was 1ml semen:4ml extender. The extended semen was divided into cervical 4 tubes added with Glutathion (GSH) at concentrations of 0.0, 0.2, 0.4 and 0.8 mM/100ml. The extended semen was kept at 5 oC for5 days. After each storage time (0, 1, 2,3, 4 and 5 days), the percentages of sperm motility, dead spermatozoa, abnormal spermatozoa, and acrosome damage of spermatozoa were recorded. Activities of aspartate-aminotransferase (AST) and alanine-aminotrans ferase (ALT) enzymes were recorded. The penetrating ability of camel spermatozoa added with 0.4 mM into she-camel cervical mucus, during incubation at 37oC for up to 4 hours was also recorded. The results showed that, the extended cooled camel semen with TYF extender was insignificantly higher the percentage of motile spermatozoa, while insignificantly lower the percentages of dead spermatozoa, abnormal spermatozoa and acrosome damage and leakage of AST and ALT enzymes into the extra cellular medium than LYC extender, during storage at 5oC for 5 days with the different concentrations of glutathione (GSH) or free – GSH medium. The advancement of storage time at 5oC for up to 5days was significantly (P<0.05) decreased the percentage of sperm motility , while increased significantly ((P<0.05) the percentages of dead spermatozoa, abnormal spermatozoa, acrosome damage and enzymatic activities(AST and ALT) with different extenders or GSH concentrations. The penetrating ability of the extended camel spermatozoa with TYF or LYC extender added with 0.4 mM/100 ml GSH into she–camel cervical mucus was significantly (P<0.05) better than free-GSH medium (control), during incubation at 37 oC for up to 4 hours. However, the advancement of incubation time at 37oC decreased significantly (P<0.05) the penetration score.

Catalase added at thawing improves dromedary camel sperm motility

Catalase added at thawing improves dromedary camel sperm motility