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.     

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.     

Use of post‐thaw semen quality parameters to predict fertility of water buffalo (Bubalus bubalis) bull during peak breeding season

This study was designed to predict the fertility of water buffalo bull using post‐thaw semen quality parameters during peak breeding season. Thirty ejaculates were collected from five bulls with artificial vagina and cryopreserved. At post‐thaw, semen was analysed for motility parameters, velocity distribution, kinematics, DNA integrity/fragmentation, viability, mitochondrial transmembrane potential, morphology, plasma membrane and acrosome integrity. Data of 514 inseminations were collected for estimation of in vivo fertility. Pearson's correlation coefficients showed that progressive motility (PM), rapid velocity, average path velocity, straight line velocity, straightness, supravital plasma membrane integrity, viable spermatozoon with intact acrosome or with high mitochondrial activity were correlated with in vivo fertility (r = .81, p < .01; r = .85, p < .01; r = .64, p < .05; r = .73, p < .05; r = .57, p < .05; r = .88, p < .01; r = .84, p < .01 and r = .81, p < .01 respectively). Step forward multiple regression analysis showed that the best single predictor of fertility was PM. However, combinations of semen quality parameters to predict fertility were better as compared to single parameter. In conclusion, fertility of buffalo bull can be predicted through some of the post‐thaw in vitro semen quality tests during peak breeding season.     

Testicular lesions and epididymal sperm parameters in the Iranian river buffalo (Bubalus bubalis)

The aim of this study was to evaluate the testicular lesions and their effects on the epididymal sperm parameters in the Iranian river buffalo (Bubalus bubalis). Total numbers of 117 scrota from the pubertal buffalo were provided from the local slaughterhouse. The samples were evaluated for morphological parameters and any macro‐ or microscopic lesions. The sterile swabs from the testis parenchyma were subjected to microbiology culture. The epididymal spermatozoon was analysed for concentration, progressive motility and abnormalities. The results showed 34.2% fibrotic adhesions between parietal and visceral layers of tunica vaginalis that was significantly different among seasons (P < 0.05). The cases of unilateral cryptorchidism and bilateral Sertoli cell tumour were detected, with no spermatozoa in the respected epididymides. Microscopic examination showed 13.25% (31/234) lesions including general (51.61%; 16/31) and multifocal (29.03%; 9/31) degenerations as well as interstitial orchitis (9.68%; 3/31) and the Sertoli cell tumour (6.45%; 2/31). No relationship between the lesions and the bacterial isolation (n = 6) was detected. The sperm parameters and morphological parameters of the testis were under influence of microscopic lesions (P < 0.05). In conclusion, the testicular macro‐ and microscopic lesions may have a noticeable contribution in the Iranian buffalo fertility.     

Seasonal variation in semen quality of swamp buffalo bulls （Bubalus bubalis） in Thailand

Aim： To test the hypothesis that season affects the semen quality of swamp buffalo （Bubalus bubalis） bulls used for artificial insemination （AI） under tropical conditions in Thailand, as it does in Bos taurus and Bos indicus. Methods： Clinical and andrological examinations, and monitoring of semen production and quality were carried out on five mature, healthy swamp buffalo AI bulls in Thailand from July 2004 to the end of June 2005. Sperm output, motility, morphology and plasma membrane integrity （PMI） were compared between three seasons of the year （rainy, i.e. July-October; winter, i.e. November-February; and summer, i.e. March-June） with distinct ambient temperature and humidity. Results： All bulls were diagnosed as clinically healthy and with good libido throughout the study. Ejaculate volume, pH, sperm concentration, total sperm number and initial sperm motility did not differ between seasons, whereas PMI and the relative proportion of morphologically normal spermatozoa were highest in summer and lowest in winter （P 〈 0.05）. Buffalo age, week of collection and season influenced sperm morphology （P 〈 0.05-0.001）. Among morphological abnormalities, only proportions of tail defects were affected by season, being highest in the rainy season and lowest in summer （P 〈 0.001）. In conclusion, climatic changes did not seem to largely affect semen sperm output or viability. Although the proportions of PMI and tail abnormalities were affected by season, they were always below what is considered unacceptable for AI bull sires. Conclusion： Seasonal changes did not appear to cause deleterious changes in sperm quality in swamp buffalo AI-sires in tropical Thailand.     

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.     

Effect of calmodulin-like protein from buffalo (Bubalus bubalis) seminal plasma on Ca2+, Mg2+-ATPase of purified plasma membrane of buffalo spermatozoa

Summary. Buffalo sperm heads and tails were cleaved by sonication and isolated in relatively pure proportions i.e. 95% and 98% respectively, by discontinuous sucrose density-gradient centri-fugation. Purified plasma membranes from the isolated sperm heads and tails were obtained by hypotonic treatment and brief sonication followed by discontinuous sucrose density-gradient centrifugation. Ca²⁺, Mg²⁺-ATPase activity was evident in plasma membrane from sperm heads and tails, although activity was greater in the latter. A calmodulin-like protein isolated from buffalo seminal plasma increased the Ca²⁺, Mg²⁺-ATPase of plasma membrane from the sperm heads and tails by 128 and 136% respectively. Based upon the data obtained here and elsewhere (Sidhu & Guraya, 1989a) a model is proposed which explains regulation of Ca²⁺ in buffalo spermatozoa and implicates calmodulin-like protein and Ca²⁺, Mg²⁺-ATPase in sperm acrosome reaction.     

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.     

l‐Cysteine improves antioxidant enzyme activity,post‐thaw quality and fertility of Nili‐Ravi buffalo (Bubalus bubalis) bull spermatozoa

The effects of l ‐cysteine in extender on antioxidant enzymes profile during cryopreservation, post‐thaw quality parameters and in vivo fertility of Nili‐Ravi buffalo bull spermatozoa were studied. Semen samples from 4 buffalo bulls were diluted in Tris–citric acid‐based extender having different concentrations of l ‐cysteine (0.0, 0.5, 1.0, 2.0 and 3.0 mm ) and frozen in 0.5‐ml French straws. The antioxidative enzymes [catalase, super oxide dismutase and total glutathione (peroxidase and reductase)] were significantly higher (P < 0.05) at pre‐freezing and post‐thawing in extender containing 2.0 mm l ‐cysteine as compared to other groups. Post‐thaw total motility (%), progressive motility (%), rapid velocity (%), average path velocity (μm s^?1), straight line velocity (μm s^?1), curvilinear velocity (μm s^?1), beat cross frequency (Hz), viable spermatozoa with intact plasmalemma (%), acrosome and DNA integrity (%) were higher with the addition of 2.0 mm l ‐cysteine as compared to other groups (P < 0.05). The fertility rates (59 versus 43%) were higher (P < 0.05) in buffaloes inseminated with doses containing 2.0 mm of l ‐cysteine than in the control. In conclusion, the addition of 2.0 mm l ‐cysteine in extender improved the antioxidant enzymes profile, post‐thaw quality and in vivo fertility of Nili‐Ravi buffalo bull spermatozoa.     

Identification of the uterine factor(s) which induce the acrosome reaction in buffalo (Bubalus bubalis) spermatozoa

This study characterizes factors present in uterine fluid from oestrous buffaloes which induce the acrosome reaction in buffalo spermatozoa. Characterization was performed by dialysis, heat treatment (90 degrees C, 30 min) and deproteinization of uterine fluid. The % motility and viability of sperm was maintained better in unfractionated uterine fluid than in dialysed fluid. Heating and deproteinization of the dialysed uterine fluid significantly reduced the % motility and viability of sperm. The percentage of sperm showing different stages of the acrosome reaction (swelling, and vesiculation) was significantly higher for sperm incubated in dialysed than in neat uterine fluid. There was no significant difference in the % of sperm showing acrosome shedding in both dialysed and neat uterine fluid. Heat treatment destroyed the ability of uterine fluid to induce the acrosome reaction. Sperm incubated in the protein precipitate from uterine fluid showed all stages of the acrosome reaction. Thus, the uterine factor(s) responsible for inducing the acrosome reaction in buffalo sperm was associated with the non-dialysable, albumin-like protein fraction and was heat-labile.     

Immunohistochemical distribution of S-100 protein and subunits (S100-alpha and S100-beta) in the swamp-type water buffalo (Bubalus bubalis) testis

The distribution and localization of S-100 protein (S-100) and its subunits (S100-alpha and S100-beta) in the testis of swamp-type water buffalo were investigated using immunohistochemistry. S-100 was detected in the Sertoli cells in the convoluted seminiferous tubules, modified Sertoli cells lining the terminal segment of the seminiferous tubules and in the intratesticular excurrent ducts (straight tubules and rete testis). S100-beta showed the same distribution and localization with that of S-100. However, the cytoplasmic extension of the Sertoli cells in S100-beta staining showed less staining intensity compared with that of S-100. S100-alpha showed a positive staining only in the modified Sertoli cells of the terminal segment of the seminiferous tubule. Endothelial cells of blood vessels were also positive with the proteins while the Leydig and spermatogenic cells showed a negative reaction. The localization of S-100 in the testis of the water buffalo was in parallel with that of other artiodactyls which supports the hypothesis that this protein is a multifunctional protein. S100-beta in the Sertoli cells suggests that this protein is involved in establishing blood-testis barrier. Its presence in the modified Sertoli cells and in the epithelium of the excurrent ducts suggest secretory and absorptive function, respectively. Meanwhile, S100-alpha, which was detected only in the modified Sertoli cells, is involved in the secretory activity of these cells that are related to exocrine function.     

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.     

Tyrosine phosphorylation of a 38-kDa capacitation-associated buffalo (Bubalus bubalis) sperm protein is induced by L-arginine and regulated through a cAMP/PKA-independent pathway

The aim of the present study was to determine the effect of L-arginine on nitric oxide (NO*) synthesis, capacitation and protein tyrosine phosphorylation in buffalo spermatozoa. Ejaculated buffalo spermatozoa were capacitated in the absence or presence of heparin, or L-arginine or N(omega)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS) for 6 h. Capacitating spermatozoa generated NO* both spontaneously and following stimulation with L-arginine and L-NAME quenched such L-arginine-induced NO* production. Immunolocalization of NOS suggested for existence of constitutive NOS in buffalo spermatozoa. L-Arginine (10 mm) was found to be a potent capacitating agent and addition of L-NAME to the incubation media attenuated both L-arginine and heparin-induced capacitation and suggested that NO* is involved in the capacitation of buffalo spermatozoa. Two sperm proteins of M(r) 38 000 (p38) and 20 000 (p20) were tyrosine phosphorylated extensively by both heparin and L-arginine. Of these, the tyrosine phosphorylation of p38 was insensitive to both induction by cAMP agonists as well as inhibition by a protein kinase A (PKA) inhibitor. Further, most of these L-arginine-induced tyrosine phosphorylated proteins were localized to the midpiece and principal piece regions of flagellum of capacitated spermatozoa and suggested that sperm flagellum takes active part during capacitation. These results indicated that L-arginine induces capacitation of buffalo spermatozoa through NO* synthesis and tyrosine phosphorylation of specific sperm proteins involving a pathway independent of cAMP/PKA.     

Testicular thermoregulation,scrotal surface temperature patterns and semen quality of water buffalo bulls reared in a tropical climate

This study evaluated the capacity of thermoregulation and its consequences on the scrotal surface temperature patterns and semen quality of buffalo bulls raised in a wet tropical climate. Eleven water buffaloes were evaluated in the rainiest, in the transitional and in the less rainy season. Air temperature and humidity were consistently high, but the animals did not show thermal stress in any season. The scrotal temperature gradient of buffalo bulls using infrared thermography was described, and three parallel and decreasing thermal bands were characterised. Sperm quality (n = 176 ejaculates) was maintained in normal parameters over the periods. Pearson's coefficients showed that sperm volume and progressive motility were negatively correlated with ocular globe, epididymal tail and minimum scrotal temperatures (p < .01). Sperm membrane integrity was negatively influenced by increases in epididymal tail and minimum scrotal temperatures (p < .01). Ocular globe temperature also showed positive correlation with rectal, spermatic cord, and epididymal tail temperatures (p < .01). Therefore, even under high temperature and humidity, the thermoregulatory system was effective in preventing heat stress and the normality of scrotal surface temperatures, spermatogenesis and sperm maturation were maintained.     

Assessment of sperm hyperactivated motility and acrosome reaction can discriminate the use of spermatozoa for conventional in vitro fertilisation or intracytoplasmic sperm injection: Preliminary results

Basic semen analysis is insufficient for determining the fertility potential. The aim of this study was to determine if hyperactivated motility (HAM) and acrosome reaction (AR) can be useful tests for evaluating semen quality during male infertility evaluations and to help the clinician decide whether regular insemination or intracytoplasmic sperm injection (ICSI) is preferable during in vitro fertilisation. A prospective study was conducted. Patients with normal sperm according to World Health Organization guidelines who underwent IVF treatment and planned regular insemination were asked to participate. A portion of sperm sample was evaluated for HAM and AR on day of ovum pick up. In HAM assessment, 93.3% of patients with increased HAM had a high fertilisation rate compared with 64% in the group without increased HAM (P = 0.059). For the AR evaluation, 91.7% of samples with a low rate of spontaneous AR had a high fertilisation rate compared with 39.3% in the group with a high rate of spontaneous AR (P = 0.004).     

Relationship between DYNLT1 and Beclin1 expression and the fertilising potential of human spermatozoa

This study aimed to evaluate dynein light chain type 1 (DYNLT1) mRNA expression in mature spermatozoa and to investigate its association with Beclin1 expression to help in understanding of pathogenesis of male infertility. It included 60 infertile men divided into idiopathic (n = 20), accessory gland inflammation (n = 20), and varicocele (n = 20) groups, and 20 healthy fertile men as a control group. Semen parameters were evaluated according to the 2010 World Health Organization criteria. Mature spermatozoa were isolated by Sil‐select gradient. Relative quantification of DYNLT1 and Beclin1 mRNA expression in whole sperm pellet and mature spermatozoa was done using real‐time PCR. Beclin1 protein was assessed in whole sperm pellet and mature spermatozoa by ELISA. Beclin1 mRNA and protein were significantly increased in spermatozoa from infertile patients of different aetiologies in comparison to healthy controls (p < .05). However, DYNLT1 mRNA expression was significantly decreased in infertile groups than controls (p < .05). Mature spermatozoa extracted from all studied subjects showed increased DYNLT1 mRNA and decreased Beclin1 mRNA and protein expression compared with the whole sample. It is concluded that decreased Beclin1 and increased DYNLT1 mRNA expression in mature spermatozoa may provide an insight into the biological processes that are activated or suppressed during sperm maturation.     

Evaluation of the acrosome reaction and viability in buffalo spermatozoa using two staining methods: the effects of heparin and calcium ionophore A23187

In this study, we investigated the effect of heparin and calcium ionophore A23187 on in vitro induction of buffalo sperm acrosome reaction (AR). Two methods for detection of the AR and viability were employed. Fluorescein isothiocyanate-conjugated Arachis hypogea agglutinin (FITC-PNA) was used as a vital stain in combination with ethidium homodimer-1 (EthD-1) to determine the acrosome status of viable spermatozoa. In another experiment, trypan blue replaced EthD-1 to differentiate live and dead spermatozoa having undergone AR. The results from the two methods were significantly correlated (r > 0.9). Four different staining patterns were found in both methods. The FITC-PNA intensely labels the acrosome region of acrosome-intact spermatozoa. EthD-1 and trypan blue stained red and blue at the post-acrosomal region of dead spermatozoa, respectively. Spermatozoa incubated with heparin showed a significant increase ( p < 0.05) in the percentage of live acrosome-reacted sperm after 30 min incubation period. This trend continued and was significantly different over the entire incubation period when compared with the control group at the same interval. In the ionophore-treated group, the proportion of changes in live acrosome-intact and live acrosome-reacted spermatozoa was statistically significantly different ( p < 0.001) when compared with those treated with heparin at the same interval. The AR occurred sooner and to a greater extent when incubated with the ionophore but at 5 h of incubation the percentage of false acrosomal reaction was significantly higher than those in the control and heparin-treated groups. The results in this study indicated that the in vitro induction of AR by heparin and calcium ionophore evaluated by both methods could be used to assess sperm fertilizing capacity for in vitro fertilization of this species.     

Molecular signalling of a novel curcumin derivative versus Tadalafil in erectile dysfunction

The efficacy of a novel curcumin derivative (NCD) versus tadalafil in erectile signalling was assessed. Ten control male rats and 50 diabetic male rats were used and divided into the following: diabetic (DM), curcumin (CURC), NCD, tadalafil and NCD combined with tadalafil rat groups. Cavernous tissue gene expression of heme oxygenase‐1 (HO‐1), Nrf2, NF‐B and p38, enzyme activities of heme oxygenase (HO) and nitric oxide synthase (NOS), cGMP and intracavernosal pressure (ICP)/mean arterial pressure (MAP) were assessed. Results showed that 12 weeks after induction of diabetes, erectile dysfunction (ED) was confirmed by the significant decrease in ICP/MAP, a significant decrease in cGMP, NOS, HO enzyme activities, a significant decrease in HO‐1 gene and a significant increase in NF‐?β, p38 genes. Administration of all therapeutic interventions led to a significant increase in ICP/MAP, cGMP levels, a significant increase in HO‐1 and NOS enzymes, a significant increase in HO‐1, and Nrf2 gene expression, and a significant decrease in NF‐?β, p38 gene expression. NCD or its combination with tadalafil showed significant superiority and more prolonged duration of action. In conclusion, a tendency was observed that CURC and NCD have high efficacy and more prolonged duration of action in enhancing erectile function.     

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.