Addition of pomegranate juice (Punica granatum) in tris‐based extender improves post‐thaw quality,motion dynamics and in vivo fertility of Nili Ravi buffalo (Bubalus bubalis) bull spermatozoa

The aim of the present study was to determine the protective effects of pomegranate juice in tris‐based extender on semen parameters, computer‐assisted sperm analysis (CASA) motion characteristics and field fertility of post‐thawed Nili Ravi buffalo (Bubalus bubalis) bull spermatozoa. Two consecutive ejaculates/collection from each of the five adult Nili Ravi buffalo bulls were collected with artificial vagina at 42°C for a period of 7 weeks, diluted in extender containing different concentrations of pomegranate juice (0.0%, 2.5%, 5%, 7.5% and 10%). Diluted samples were packed and frozen in 0.54 ml French straws. The addition of 10% pomegranate juice in extender significantly improved post‐thaw sperm morphology (%), motilities (CASA total motility, progressive motility (%) as well as VAP, VSL, VCL, STR, DAP, DSL) compared to the control group (p < 0.05). Plasma membrane, acrosome membrane and DNA integrity were significantly higher in extender with 10% pomegranate juice than the control group (p < 0.05). Field fertility rate (60.39% vs. 46.53%) was higher (p < 0.05) in extender with 10% pomegranate juice as compared to the control. It is therefore concluded that the addition of 10% pomegranate juice in tris‐based extender improves post‐thaw semen parameters, CASA motion dynamics and field fertility in Nili Ravi buffaloes.     

Programmable fast‐freezing method improves the post‐thaw motion dynamics,integrities of plasmalemma,mitochondrial transmembrane,DNA and,acrosome, and in vivo fertility of water buffalo (Bubalus bubalis) spermatozoa

The effects of freezing methods (FR1, nonprogrammable/static, 5 cm above liquid nitrogen [LN₂] for 10 min, plunging in LN₂; FR2, programmable medium, +4°C to ?15°C at 3°C min^?1, from ?15 to ?80°C at 10°C min^?1 and final holding for 1 min at ?80°C, plunging in LN₂; FR3, programmable fast, from initial holding at +4°C for 2 min, from +4°C to ?20°C at 10°C min^?1, from ?20°C to ?100°C at 30°C min^?1, final holding for 1 min at ?100°C and plunging in LN₂) were assessed on post‐thaw in vitro quality and in vivo fertility of water buffalo spermatozoa. Mean sperm progressive motility (%), rapid velocity (%), average path velocity (μm s^?1), straight line velocity (μm s^?1), curved line velocity (μm s^?1), integrities (%) of plasmalemma, mitochondrial transmembrane, DNA and acrosome were higher (p < .05) in samples cryopreserved with FR3 compared to FR1 and FR2. Similarly, in vivo fertility (%) of buffalo spermatozoa was higher (p < .05) with FR3 than FR1 (%; 68.0 versus 50.0). We concluded that programmable fast‐freezing method (FR3) improves the post‐thaw in vitro quality and in vivo fertility of water buffalo spermatozoa.     

Comparison of Tris egg yolk‐based,Triladyl® and Optixell® extender on post‐thaw quality,Kinematics and in vivo fertility of Nili Ravi Buffalo (Bubalus bubalis) bull spermatozoa

Our objectives were to ascertain the comparison of Tris egg yolk‐based, Triladyl ^® and Optixell ^® extender on postthaw quality, CASA parameters and in vivo fertility of Nili Ravi buffalo (Bubalus bubalis) bull spermatozoa. Semen samples (n = 35) from five bulls were diluted in Tris egg yolk‐based, Triladyl ^® , Optixell ^® extender and frozen in 0.50 ml French straws. Postthaw sperm CASA motility (%) was higher (p < 0.05) in Optixell extender as compared to Triladyl and Tris egg yolk‐based extender. Although sperm progressive motility (%), morphology (%), average path velocity (μm/s), straight line velocity (μm/s), curvilinear velocity (μm/s), amplitude of lateral head displacement (μm), beat cross‐frequency (Hz), straightness (%), length of curvilinear path (μm), length of average path (μm), intact plasma and acrosome membrane (%), and DNA integrity (%) were higher (p < 0.05) in spermatozoa cryopreserved in Optixell ^® extender as compared to Tris egg yolk‐based and Triladyl ^® extender. The fertility rates (68.18%, 45.45%, 55.4%) were higher (p < 0.05) in buffaloes inseminated with semen doses frozen in Optixell extender than the Tris egg yolk‐based and Triladyl ^® extender respectively. It is concluded that Optixell ^® extender improves postthaw semen quality and fertility in Nili Ravi buffaloes.     

Cryoprotectant effect of trehalose in extender on post‐thaw quality and in vivo fertility of water buffalo (Bubalus bubalis) bull spermatozoa

This study was designed to ascertain the cryoprotectant effects of different concentrations of trehalose [0 (T0), 25 (T25), 35 (T35), 45 (T45) mm ], egg yolk [20% (E20), 15% (E15) v/v] and glycerol [7% (G7), 5% (G5) v/v] in Tris‐citric acid‐based extender on post‐thaw quality and in vivo fertility of buffalo bull spermatozoa. Twenty‐five ejaculates were collected from five bulls and split into four parts. After that, the split ejaculates from each of the bull were diluted either in T0E20G7 (control) or T25E20G5 or T35E15G5 or T45E15G5 extender. Finally, the sperm suspension was frozen in 0.54‐ml French straws. Post‐thaw sperm total motility (%), progressive motility (%), rapid velocity (%), average path velocity (μm/s), straightline velocity (μm/s), curvilinear velocity (μm/s), linearity (%), plasma membrane and acrosome integrities (%) were higher (p < .05) in T45E15G5 extender as compared to other treatment groups and control. The fertility rate (56.8% versus 41.3%) was higher (p < .05) in buffaloes inseminated with semen doses cryopreserved in extender containing T45E15G5 combination of cryoprotectants than the control. In conclusion, addition of 45 mm trehalose along with 15% egg yolk and 5% glycerol in extender improves the post‐thaw quality and in vivo fertility of buffalo bull spermatozoa.     

Trehalose enhances osmotic tolerance and suppresses lysophosphatidylcholine‐induced acrosome reaction in ram spermatozoon

This study was aimed to investigate the influence of trehalose on osmotic tolerance and the ability of ram spermatozoon to undergo acrosome reaction induced by lysophosphatidylcholine (LPC). In experiment 1, the diluted ejaculates were exposed to anisosmotic fructose solutions (70, 500, 750 and 1000 mOsm l^?1) with or without 50 mm trehalose. The presence of trehalose in hyperosmotic conditions enhanced (P < 0.05) the percentage of live, live‐intact and intact spermatozoa. Similarly, trehalose enhanced (P < 0.05) the live and live‐intact spermatozoa during hypo‐osmotic conditions. In experiment 2, the centrifuged ejaculates were diluted with TCG only or TCG containing either 50 or 100 mm trehalose. The acrosome reaction was induced by LPC. The percentage of acrosome‐reacted spermatozoon was less (P < 0.05) in trehalose‐supplemented groups compared to control. In experiment 3, the ejaculates were cryopreserved in an extender containing 0 mm (control), 50 mm or 100 mm trehalose. Supplementation of extender with trehalose, either 50 mm or 100 mm , enhanced the cryosurvival rate (P < 0.05) compared to the control. In conclusion, the presence of trehalose in anisosmotic conditions enhances the osmotic tolerance, cryosurvival rate of ram spermatozoon and suppresses their ability to undergo LPC and cryo‐induced acrosome reaction.     

Effect of cysteine and glutamine added to extender on post‐thaw sperm functional parameters of buffalo bull

Amino acids seem to be crucial components for semen freezing extender due to antioxidant properties. Therefore, this study aimed to assess motility parameters, membrane integrity, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and DNA damage to detect the optimum concentrations of cysteine and glutamine for buffalo semen cryopreservation. Twenty ejaculates of four buffalo bulls were diluted in tris‐egg yolk extender and divided into seven equal groups consisting of cysteine (5, 7.5 and 10 mmol), glutamine (10, 15 and 20 mmol) and no additive. Supplementation of 5 and 7.5 mmol cysteine and 15 mmol glutamine in cryopreservation extender significantly increased post‐thaw motility and plasma membrane integrity of spermatozoa with significant reduction in intracellular ROS when compared with control groups (P < 0.05). Cysteine at 7.5 mmol concentration elevated progressive motility and MMP, compared with control (P < 0.05). No significant differences were observed for motion patterns and DNA damage of frozen–thawed buffalo spermatozoa in extender containing amino acids. The findings of this study showed that supplementation of 7.5 mmol cysteine and 15 mmol glutamine in semen cryopreservation extender has more potential to decrease intracellular ROS, and subsequently elevate motility and membrane integrity of buffalo frozen–thawed spermatozoa.     

Survival of buffalo bull spermatozoa: effect on structure and function due to alpha‐lipoic acid and cholesterol‐loaded cyclodextrin

Sperm survival depending upon integral membranes and function is imperative for fertilization. This study was designed to augment survival of buffalo spermatozoa using alpha‐lipoic acid (ALA) and cholesterol‐loaded cyclodextrin (CLC) during cryopreservation. Semen was frozen using 0, 0.5, 1, 1.5, 2 and 2.5 mmol L^?1 ALA (experiment 1) and ALA or CLC separately or together (experiment 2). Semen was assessed for post‐thaw motility, plasma membrane integrity (PMI), intact acrosome and plasma membrane (IACR‐IPM) and DNA integrity at 0, 1.5, 3 and 4.5 hr of incubation. In experiment 1, use of 0.5 mmol L^?1 ALA enhanced the sperm cryosurvival and post‐thaw longevity than other groups up to 4.5 hr of incubation, and this concentration of ALA was used in second experiment with CLC. The results revealed higher (p < .05) sperm survival function and time of sperm attributes due to use of ALA than CLC and control. However, the sperm quality did not improve (p > .05) when ALA was combined with CLC. In conclusion, survival of buffalo bull spermatozoa during freeze‐thawing and post‐thaw incubation can be enhanced more with ALA than CLC or control, followed by CLC than control. However, there is no synergistic effect on survival of buffalo bull spermatozoa due to ALA and CLC.     

Cryoprotective effect of l‐carnitine on motility,vitality and DNA oxidation of human spermatozoa

Successful cryopreservation for human spermatozoa markedly influences the reproductive outcomes of assisted reproductive technologies. But in spite of its usefulness, cryopreservation significantly decreases sperm quality. l ‐carnitine has been found to improve the quality of spermatozoa in selected cases with male infertility. Here, we examined the efficacy of l ‐carnitine in improving sperm motility and vitality and reducing sperm DNA oxidation during cryopreservation. Semen samples from infertile patients (n = 22) were collected and analysed. Cryopreservation medium supplemented with l ‐carnitine was mixed with the semen at a ratio of 1 : 1 (v/v). The final l ‐carnitine concentration in each cryovial was 0.5 mg ml^?1 per 5 × 10⁶ cell ml^?1. Controls were cryopreserved without addition of l ‐carnitine. After 24 h of cryopreservation, thawed sperm samples were analysed for motility, vitality and DNA oxidation. Sperm vitality was assessed by the eosin–nigrosin test, while sperm DNA oxidation was measured by flow cytometry. Addition of l ‐carnitine significantly improved sperm motility and vitality (P < 0.05) compared with the control. The flow cytometry experiment showed no statistical difference (P > 0.05) in the levels of DNA oxidation between samples and controls. In conclusion, l ‐carnitine improves human sperm motility and vitality, but has no effect on sperm DNA oxidation after cryopreservation.     

Effect of l‐arginine addition on long‐term storability of ram semen

This study was conducted to investigate the effect of l ‐arginine addition on long‐term storability of ram semen. Six Akkaraman rams were used as material. Semen samples were collected. Pooled samples were diluted and were divided into six equal aliquots. While aliquot 1 was kept as control, the stock solutions including 0.1, 0.5, 1, 5 and 10 mm l ‐arginine were added to other aliquots. All aliquots were routinely frozen in 0.25‐ml straws at ?130°C liquid nitrogen vapour and stored in liquid nitrogen ?196°C until being analysed. The equilibrated and thawed sperm motility, membrane integrity and arginase activity were evaluated. While the 10 mm l ‐arginine supplementation significantly (p < .001) decreased equilibrated sperm motility, the 5 mm significantly (p < .05) increased the membrane integrity and arginase activity in comparison with the control group. The motility (p < .001) and membrane integrity (p < .01) were determined to be highest in 0.5 mm group, while significant reductions were observed in motility (p < .001) of 10 mm group and arginase activity (p < .05) of 1, 10 mm groups as compared to the control group. It was concluded that in vitro addition of 0.5 mm l ‐arginine to ram semen may be useful, but 10 mm may be harmful to spermatozoa quality during long‐term storage.     

Anti‐oxidative Status and Semen Quality during Cooled Storage in Stallions

Activity of the anti‐oxidative enzymes glutathione peroxidase (GSH‐Px), superoxide dismutase (SOD) and catalase (CAT), content of thiobarbituric acid reactive substances (TBARS) and SH‐groups were determined in native stallion semen (n = 8 stallions). Semen was then diluted in Kenney extender, EquiPro^® extender either with or without addition of N‐acetyl cysteine or phosphate‐buffered saline (PBS) and stored for 72 h at 5°C. Correlations between initial activity of enzymes and development of semen motility and membrane integrity were calculated. Activities of GSH‐Px, SOD and CAT immediately after semen collections were 10.0 ± 0.6 picokatals, 0.40 ± 0.03 SOD units and 0.70 ± 0.05 nanokatals/10⁶ spermatozoa respectively. TBARS content was 0.06 ± 0.01 nmol and SH‐group content 1.7 ± 0.5 mmol/10⁶ spermatozoa. The loss of motile spermatozoa during storage did not differ between extenders. N‐acetyl cysteine had no effect on semen motility and membrane integrity. The loss in membrane‐intact spermatozoa was highest (P < 0.05) in semen diluted in PBS. Motility and membrane integrity after addition of extender were positively correlated with GSH‐Px and CAT, indicating that anti‐oxidative mechanisms contribute to the initial high percentage of motile and membrane‐intact spermatozoa. However, in these samples the decrease in semen quality was most pronounced. No correlations existed between initial activity of anti‐oxidative enzymes, peroxidation products and semen quality during storage. This indicates that once extender has been added, peroxidative damage to sperm membranes is not the predominant cause of losses in semen quality.     

Impact of using a fast‐freezing technique and different thawing protocols on viability and fertility of frozen equine spermatozoa

The effects of freezing technique and thawing protocol on thawed semen viability and fertility were studied. Ejaculates from 5 stallions (n = 25) were frozen by conventional or a fast‐freezing technique. Frozen semen was thawed by two thawing protocols (37 °C 30 s^?1 or 75 °C 7 s^?1). Thawed semen was evaluated by progressive motility, vigour, morphology and plasma membrane integrity. Mares (n = 25) were inseminated with 300 (n = 11) or 150 (n = 14) million spermatozoa. A greater (P < 0.05) vigour and progressively motile spermatozoa were detected, respectively, at thawing and after 20 min post‐thawing in the fast‐freezing technique than in the conventional one. Plasma membrane integrity was also greater (P < 0.05) in semen frozen with the fast‐freezing technique. Semen viability was not affected by thawing protocol. Pregnancy rate using the fast‐freezing technique was 76% (19/25), and did not differ (P > 0.05) between insemination doses. We concluded that the 150 million progressively motile spermatozoa per dose using a deep‐horn insemination maximises the use of equine semen. The fast‐freezing technique, as compared to the conventional one, efficiently preserves the viability and fertilising capacity of spermatozoa, indicating a new method to improve the fertility of frozen equine semen.     

Isolation of bacteria in semen and evaluation of antibiotics in extender for cryopreservation of buffalo (Bubalus bubalis) bull spermatozoa

This study was designed to investigate the occurrence of bacterial species in water buffalo semen at the time of collection/processing and to assess the efficacy of some selected antibiotics (GTLS; gentamycin, tylosin and linco‐spectin or SP; streptomycin and penicillin) in cryodiluent on bacterial control and quality including in vivo fertility of buffalo spermatozoa. For this purpose, four experiments were conducted. In experiment 1, a total of 11 bacterial species were isolated from buffalo ejaculates. In experiment 2, total aerobic bacterial counts at post dilution and thawing were lower (P < 0.05) in GTLS than in SP or control. The majority of the bacterial isolates from ejaculates were more susceptible to GTLS than SP. In experiment 3, sperm acrosome integrity was higher (P < 0.05) in GTLS and SP compared to control. In experiment 4, the in vivo fertility results for GTLS were higher (P < 0.05) than that for SP. In conclusion, a number of bacterial species were isolated from the bubaline semen, which requires an efficient control before its use in artificial insemination program. The GTLS combination of antibiotics may be incorporated into a freezing extender/protocol without compromising the post‐thaw quality and in vivo fertility of buffalo bull spermatozoa.     

Conventional slow freezing cryopreserves mouflon spermatozoa better than vitrification

This work examines the effectiveness of a TCG (Tris, citric acid, glucose, 6% egg yolk and 5% glycerol) and a TEST (TES, Tris, glucose, 6% egg yolk and 5% glycerol) sperm extender in the freezing of mouflon spermatozoa at slow cooling rates, using different pre‐freezing equilibration times (2–3 hr). It also examines the tolerance of mouflon spermatozoa to different concentrations of cryoprotectants (5, 10, 20% glycerol; 5%, 10%, 20% dimethyl sulfoxide; 6% polyvinylpyrrolidone) and/or sucrose (100, 300, 500 mm ). The highest quality (p < .01) thawed spermatozoa were obtained when using the TEST extender and an equilibration time of 3 hr. Sperm motility and membrane integrity were strongly reduced when using rapid freezing rates (60–85°C min^?1), independent of the concentration of cryoprotectants. The lowest sucrose concentration (100 mm ) provided the highest (p < .05) percentage of motile spermatozoa and live spermatozoa with an intact acrosome. Vitrified–warmed sperm variables were at their best when the spermatozoa was diluted in TCG–6% egg yolk + 100 mm sucrose and warmed at 60°C. Slow warming at 37°C strongly reduced (p < .05) sperm motility and viability. However, sperm vitrification returned lower fertility, sperm motility and sperm viability values than conventional sperm freezing.     

Freezability of water buffalo bull (Bubalus bubalis) spermatozoa is improved with the addition of curcumin (diferuoyl methane) in semen extender

Effects of curcumin as antioxidant in extender were evaluated on freezability of buffalo spermatozoa. Semen from each of the five bulls (n = 3 replicates, six ejaculates/bull, a total of 30 ejaculates) was diluted in Tris‐citric acid extender containing curcumin (0.5, 1.0, 1.5 or 2.0 mM) or control. At pre‐freezing and post‐thawing, total antioxidant contents (μM/L) and lipid peroxidation levels (μM/ml) were higher (p < .05) and lower (p < .05) respectively, with 1.5 and 2.0 mM compared to 0.5 and 1.0 mM curcumin and control. At post‐thawing, progressive motility (PM, %) and rapid velocity (RV, %) were higher (p < .05) with 1.5 mM compared to other doses of curcumin and control (except in case of RV, 1.5 was similar with 1.0 mM). Kinematics (average path velocity, μm/s; straight‐line velocity, μm/s; curved‐line velocity, μm/s; straightness, %; linearity, %), in vitro longevity (%, PM and RV) and DNA integrity (%) at post‐thawing were higher (p < .05) with 1.5 mM compared to control. At post‐thawing, supravital plasma membrane integrity (%) and viable spermatozoa with intact acrosome (%) were higher with 1.5 compared to 2.0 mM curcumin and control. We concluded that freezability of water buffalo spermatozoa is improved with the addition of 1.5 mM curcumin in extender.     

Short‐term storage of salmonids semen in a sodium alginate‐based extender

Short‐term storage of semen is a useful strategy for preservation of fish spermatozoa. However, there is a significantly decrease on sperm function mainly due to oxidative stress. In this way, sodium alginate plays an important role as free radical scavenger compound. Accordingly, the aim of our study was to analyse the effect of a sodium alginate‐based extender on sperm function in the short‐term storage of salmonids semen. Samples of Salmo salar, Oncorhynchus kisutch, and Oncorhynchus mykiss were stored in Storfish^® (Ext‐C) and Storfish^® supplemented with sodium alginate (Ext‐A) during 10 days at 4°C. After storage, motility, viability, mitochondrial membrane potential (ΔΨmit), superoxide anion (O₂^?) level and DNA fragmentation (DNA Frag) were assessed. Ext‐A had positive effect in preservation of sperm motility, viability, ΔΨmit, O₂^? level and DNA integrity in the three species analysed compared to control samples. In Ext‐A, the spermatozoa of S. salar and O. mykiss showed significantly higher motility, viability and ΔΨmit than O. kisutch. However, O. kisutch and O. mykiss had significantly lower O₂^? level than S. salar, and DNA fragmentation in O. kisutch and S. salar was significantly lower than in samples of O. mykiss (p < 0.05). Dilution of salmonids semen in a sodium alginate‐based extender is effective for protecting sperm quality during 10 days of short‐term storage.     

Testosterone and high‐sensitive C‐reactive protein in coronary artery disease patients awaiting coronary artery bypass graft

Natural androgens inhibit atherosclerosis in men. This study aimed to examine whether testosterone and high‐sensitive C‐reactive protein differ between patients with coronary artery disease and those without coronary artery disease and to determine the association with the severity of coronary artery disease. Two hundred and six male subjects were recruited. Serum total testosterone and high‐sensitive C‐reactive protein were estimated. Severity of coronary artery disease was assessed by angiographic scores. Total testosterone level in patients was significantly different from controls (11.4 ± 2.7 vs. 18.1 ± 7.2 nm P = 0.001) and high‐sensitive protein level in cases was significantly higher compared to controls (3.37 ± 1.62 mg l^?1 vs. 1.71 ± 0.60 mg l^?1, P = 0.001). Testosterone levels were not significantly different with vessel (P = 0.592), Leaman (P = 0.694) and Gensini (P = 0.329) score groups, but high‐sensitive C‐reactive protein showed significant positive correlation among the respective groups (P = 0.005, P = 0.028, P = 0.015). Testosterone was lower, while high‐sensitive C‐reactive protein was higher in patients compared to controls. Testosterone showed no correlation with the severity of atherosclerosis, but high‐sensitive C‐reactive protein showed significant positive correlation.     

Antioxidant activity of Nigella sativa Seeds Aqueous Extract and its use for cryopreservation of buffalo spermatozoa

The free radical scavenging activity (RSA) of Nigella sativa extract and its efficiency for cryopreservation of buffalo spermatozoa was investigated. In experiment 1, Nigella sativa extract was prepared and evaluated for RSA using 2,2‐diphenyl‐1‐picrylhydrazyl assay. The results showed increased pattern of RSA at 1%–5% of Nigella sativa extract. In experiment 2, buffalo semen from three bulls (24 ejaculates) was incubated at 0%, 0.1%, 0.3%, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5% and 6% extract to assess in vitro tolerability to Nigella sativa in terms of progressive motility (PM). Buffalo spermatozoa showed tolerance to all levels; rather, sperm PM was increased at 1%–4% extract. In experiment 3, semen from three bulls (24 ejaculates) was cryopreserved with 0%, 1%, 2%, 3%, 4% and 5% of Nigella sativa extract. Sperm PM and plasma membrane integrity (PMI) were evaluated after dilution and cooling, while PM, PMI, viability and DNA integrity were evaluated after thawing. Nigella sativa extract at 4% in extender improved (p < .05) post‐dilution, post‐cooling and post‐thaw sperm quality. In conclusion, Nigella sativa extract at all concentrations (1%–6%) showed antioxidant activity and its supplementation at 4% in extender improved buffalo sperm quality at all stages of cryopreservation.     

Ultrastructure evaluation of goat spermatozoa after freezing in a skim milk‐based extender with Trolox supplementation

The aim of this work was to evaluate the in vitro effect of adding Trolox in freezing extender for goat semen. Ejaculates from five bucks were evaluated, and when approved, the samples were pooled, diluted according to experimental groups [Trolox 0 (control), 30, 60 and 120 nmol ml^?1] and frozen in an automated system. Thawed samples (37 °C/30 s) were evaluated for plasma membrane (PMi) and acrosome integrity (Aci), mitochondrial membrane potential (MMP) and sperm kinematics by CASA system. Spermatozoa ultrastructure was evaluated in fresh and post‐thawed semen. No significant difference (P > 0.05) was observed among control and Trolox groups in the analyses of PMi, Aci, MMP and CASA in goat spermatozoa after thawing. Samples of 60 and 120 nmol ml^?1 Trolox groups had a higher percentage of cells that had intact plasma membranes in spermatozoa head than in the other groups, although they did not differ (P > 0.05) before being frozen. A higher percentage (P < 0.05) of spermatozoa with intact mitochondria was observed in fresh semen, control and Trolox 60 nmol ml^?1 groups than in the other groups. Addition of Trolox to skim milk extender at 60 nmol ml^?1 ultrastructurally preserves the plasma membrane and mitochondrial sheath integrity in goat spermatozoa after cryopreservation.     

A new approach for cryoprotectant‐free freezing of goat epididymal spermatozoa

A cryoprotectant‐free method was successfully used for rapid freezing of goat epididymal spermatozoa. Lowering sperm volume may increase the temperature exchange rate and improve the freezing output of spermatozoa. The aim of this study was to compare two different packaging types [0.25 ml French straws (FS) and 96‐well immune plate (WIP)] for rapid freezing of goat epididymal spermatozoa. Eleven pairs of the goat testes were transferred to the laboratory; cauda epididymidides were dissected and sliced in TRIS‐BSA solution for 15 min and temperature 33–35 °C. Sperm concentration was adjusted to 20 × 10⁶ ml^?1, and the suspension was subjected to rapid freezing within FS or WIP. The volume of spermatozoa in WIP method was set at 25 μl. Sperm motility, viability and abnormalities, and sperm DNA integrity were compared between two devices. The results showed similar effectiveness of WIP and FS on post‐thaw sperm parameters. In conclusion, for cryoprotectant‐free rapid freezing of goat epididymal spermatozoa, it is recommended to use WIP instead of French 0.25 ml straws.     

In vitro effects of nonylphenol on motility,mitochondrial, acrosomal and chromatin integrity of ram and boar spermatozoa

The objective of this study was to determine the effects of nonylphenol (NP) on viability of ram and boar sperm in vitro. Ram or boar spermatozoa were exposed to 1, 10, 100, 250 and 500 μg NP ml^?1 for 1, 2, 3 or 4 h. Computer‐assisted sperm motility analysis (CASA) system was used to evaluate sperm motility characteristics. Flow cytometry was used to determine mitochondrial membrane potential (MMP) and chromatin integrity, while epifluorescent microscopy was used to determine sperm acrosomal status. Exposure of both species spermatozoa to 250 and 500 μg NP ml^?1 was detrimental to progressive motility (P < 0.05), and its adverse effect was significant at lower (100 μg NP ml^?1) concentration (P < 0.05). The percentages of ram and boar spermatozoa with high MMP declined drastically after exposures to ≥250 μg ml^?1 NP (P < 0.05). Unlike chromatin integrity, which did not appear to be altered by NP exposure, there were dose‐dependent NP effects (P < 0.05) on acrosomal integrity of both species at as low as 1 μg ml^?1 NP for boar spermatozoa and 10 μg ml^?1 NP for ram spermatozoa. These data show adverse effects of NP on ram and boar spermatozoa and thus its potential harmful effects on male reproduction as NP is found in fruits, vegetables, human milk, fish and livestock products.