Validation of the sperm quality analyzer (SQA) for dog sperm analysis

Rheotaxis quality index: a new parameter that reveals male mammalian in vivo fertility and low sperm DNA fragmentation

The female reproductive tract simultaneously guides and selects high-quality sperm using rheotaxis in mammalian species. Sperm quality, however, is traditionally evaluated only by their movement velocities and concentration using computer-assisted sperm analysis (CASA), which ignores sperm rheotaxis. Here, by mimicking the female reproductive tracts' dimensions and hydrodynamic features, a new method is introduced to quantify sperm rheotaxis ability for evaluating semen quality. The combination of our RHEOtaxis quaLity indEX (RHEOLEX) and motile sperm concentration is able to predict sperm fertility levels in artificial insemination at various shear rates within 5 minutes. This means that RHEOLEX could be a biomarker for determining male in vivo fertility, unlike conventional semen quality parameters which fail to provide statistically significant predictions. In addition, a high RHEOLEX is associated with a low DNA fragmentation index (DFI), showing that this new parameter is able to identify low-DFI samples. Not only does this work highlight the importance of rheotaxis in determining male in vivo fertility, but it also provides a solid benchmark for developing fast microfluidic devices for male fertility prediction as well as DFI. Last, the data imply that the female reproductive tract might use rheotaxis to keep sperm with fragmented DNA from reaching the fertilization site.

Evaluation of sperm morphometry of rabbits (Oryctolagus cuniculus f. domesticus)

Sperm morphology and morphometry are considered parameters in fertility diagnosis. They are especially important in the case of species for which there is no standard with respect to morphometric sperm parameters. It is then crucial to apply the staining technique that has the least influence on the sperm structure and provides the most detailed image, so as to enable measurements. The aim of the research was to assess the morphometric parameters of rabbit sperm using silver nitrate staining. The staining process revealed a detailed image of the spermatozoon head and tail, thus enabling precise measurements. From these basic morphometric parameters, four additional shape indices characterizing the sperm head were calculated: ellipticity, elongation, roughness and regularity. These parameters more precisely characterize the shape of the sperm head. Silver nitrate staining can be used as an independent technique in assessment of sperm structure or to supplement routine diagnostics.

The effect of the staining technique on morphological and morphometric parameters of boar sperm

Sperm morphology and morphometry are important parameters in predicting fertility. Sperm are considered to be normal if the shape and size of the head, midpiece and tail fall within the classification for a given species. It is important to select the appropriate technique for staining the semen of a given species, because, as many authors have pointed out, some methods work well for one species but are not suitable for analysing another. The aim of the study was to assess the morphometric parameters of boar sperm following the use of different staining techniques and to verify the hypothesis that the staining technique affects the morphometric parameters of sperm. The staining method was found to significantly affect the dimensions of the boar sperm head. The semen stained by the SpermBlue technique had the closest morphometric sperm head parameters to those of the unstained sperm, so this technique, rather than the routinely used eosin and gentian complex, should be the leading technique in the evaluation of boar sperm morphometry. Silver nitrate staining reveals the structure of the sperm in the most detail; this method can be considered universal, and can be used independently or to supplement routine diagnostics. As the staining technique should interfere as little as possible with the structure of the sperm, while revealing its morphology in as much detail as possible, it is crucial to establish the natural dimensions of the unstained sperm head before determining the optimal technique and its reference values. The recommended or most commonly-used techniques are not always the best options for the staining and analysis of sperm of a given species.

Double-blind prospective study comparing two automated sperm analyzers versus manual semen assessment

PURPOSE

Despite controversy regarding its clinical value, male fertility investigation mainly relies on semen analysis. Even though reference guidelines are available, manual sperm analysis still suffers from analytical variability, thus questioning the interest of automated sperm analysis systems. The aim of this study is to compared automated computerized semen analysis systems (SQA-V GOLD and CASA CEROS) to the conventional manual method in terms of accuracy and precision.

METHODS

We included 250 men in this double-blind prospective study. The SQA-V GOLD (Medical Electronic Systems) and CEROS, CASA system (Hamilton Thorne) were compared to the standard manual assessment based on the WHO 5th Edition. The main outcome measures were sperm concentration, total sperm number, total motility, progressive motility, non-progressive motility, morphology, motile sperm concentration (MSC) and progressively motile sperm concentration (PMSC) with the three methods.

RESULTS

Statistical analysis of the test results from the automated systems and the manual method demonstrated no significant differences for most of the semen parameters. The Spearman coefficients of rank correlation (rho) for CASA and the SQA-V GOLD automated systems vs. the manual method were: Sperm concentration (0.95 and 0.95), total sperm number (0.95 and 0.95), MSC (0.94 and 0.96) and PMSC (0.94 and 0.93) correspondingly. Concerning sperm morphology, both automated systems demonstrated high specificity (Sp) and negative predictive values (NPV), despite significantly different medians (CASA: 83.7 % for Sp and 95.2 % for NPV, SQA-V: 97.9 % for Sp and 92.5 %). The highest precision (lowest 95 % confidence interval for duplicate tests) for all semen variables was found in the SQA-V GOLD.

CONCLUSIONS

The advantages of using automated semen analysers are: Standardization, speed (lower turnaround time), precision, reduced potential for human error, automated data recording and less need for highly skilled professionals to run the systems. The disadvantages of using automated systems are: notably the problem with testing some atypical samples and the inability to perform an assessment of morphology abnormalities. Based on the results of this study, the SQA-V Gold demonstrated better agreement vs. the manual method. In conclusion, automated semen analyzers can be used for routine semen analysis providing rapid clinically acceptable results with higher precision, and positively impacting laboratory standardization.

Influence of cool storage before freezing on the quality of frozen-thawed semen samples in dogs

The aim of this study was to determinate the semen quality of frozen-thawed samples that were chilled for up to 2 days before freezing. The ejaculates (n = 18) from six dogs were collected, pooled and divided into six aliquots. The first aliquot (C, control) was frozen in liquid nitrogen using a conventional protocol to reach a final concentration of 100 × 10(6) spermatozoa/ml, 20% egg yolk and 5% glycerol. The remaining five aliquots were diluted with a chilled extender (Tris-glucose and 20% egg yolk) and cooled at 4 °C as follows: R1, the semen was cooled for 1 h; R6, the semen was cooled for 6 h; R12, the semen was cooled for 12 h; R24, the semen was cooled for 24 h and R48, the semen was cooled for 48 h. After the chilling period, a second extender was added (Tris-glucose, 20% egg yolk, 10% glycerol and Equex at 1%) to reach a final composition similar to aliquot C, and then, the semen samples (R1, R6, R12, R24 and R48) were frozen in liquid nitrogen. The post-thaw sperm quality was assessed in 30 straws from each experimental group. After freezing-thawing, the total sperm motility (approximately 60-70%) in the semen chilled for up to 48 h did not show any differences from the samples frozen by the conventional cryopreservation method (63.2%). No significant differences were detected in the percentages of abnormal sperm cells among the fresh semen, the control group and the frozen samples after the different cooling times. Finally, the post-thaw percentages of damaged acrosomes showed a very uniform distribution, with mean values ranging between 7% and 10.5%. The results clearly demonstrated that cooling the semen up to 48 h before freezing did not produce a decrease in the semen quality when was compared with semen frozen by a traditional procedure.

Use of a new computer-assisted sperm analyzer for the assessment of motility and viability of dog spermatozoa and evaluation of four different semen extenders for predilution

The aims of this study were to evaluate a new computer-assisted sperm analyzer (CASA; SpermVision, Minitüb, G) for the analysis of canine spermatozoa, and to suggest suitable semen diluents that should influence motility and viability parameters to the lowest extent. For these purposes, the sperm-rich fractions from 40 ejaculates were diluted with either saline (S), PBS, autologous prostate secretion (third fraction, PROST) or a modified TRIS buffer (TRIS; [Pena, A., Johannisson, A., Linde-Forsberg, C., 1999. Post-thaw evaluation of dog spermatozoa using new triple fluorescent staining and flow cytometry. Theriogenology 52, 965-980]). Viability was investigated both objectively with SYBR-14/PI in SpermVision and subjectively with carboxyfluoresceindiacetate (CFDA) fluorescence stains by optical microscopy. For all diluents and for most parameters, the intra- and inter-assay coefficients of variation were below 10% and 20%. Effects after dilution with TRIS and PROST were similar, but only after dilution with TRIS, total motility significantly correlated with estimated motility in raw semen (P<0.01, R=+0.514). After dilution, estimated and measured motility values were positively related, but correlated significantly with PBS only (P<0.01). After dilution with PBS and S, all motility parameters were significantly lower in comparison with PROST and TRIS, and after dilution with PBS, significantly more membrane damages occurred than with TRIS, S and PROST (P<0.05, <0.05 and <0.01). In samples diluted with TRIS, membrane integrity of spermatozoa determined with SYBR-14/PI and CFDA staining correlated significantly (R=+0.686; P<0.01). Concerning the location of membrane damages, no differences appeared after dilution with different media. In conclusion, SpermVision proved to be an accurate analyzer for the objective assessment of both motility and viability of canine spermatozoa. TRIS and PROST were the media with the lowest influences on parameters of canine semen, and are therefore recommendable for the use in SpermVision.

Effect of body weight, age and breeding history on canine sperm quality parameters measured by the Hamilton-Thorne analyser

During the last decade, several computer assisted sperm analysis (CASA) systems have been validated for canine sperm quality assessment. Regarding the impressive possibilities of these systems, further research is required to determine which CASA measurements are of clinical importance in canine andrology. In the present study, the sperm quality parameters obtained by the Hamilton-Thorne Semen Analyser (Ceros 12.1; HTR) were correlated with the body weight and the age of the dogs. Moreover, the sperm quality parameters of dogs with a different breeding history were compared. The sperm-rich fraction was collected from 111 dogs of 50 different breeds, which were presented at our department. Immediately after collection, the concentration, the total sperm output (TSO) and 13 different sperm motility and velocity characteristics were measured by the HTR. The percentage of live spermatozoa and the spermatozoal morphology were examined on eosin/nigrosin stained smears. Based on their breeding history, the dogs were divided in three groups: 'fertile' (n = 60), 'subfertile' (n = 17) or 'not used for breeding' (n = 34). Significant (p < 0.05) correlations were established between the body weight of the dogs and the TSO (r = 0.245) and velocity curvilinear (VCL; r = -0.220), respectively. The age was negatively correlated with the percentage of normal spermatozoa (r = -0.203; p < 0.05). The correlations with all the other evaluated sperm parameters were low and not significant. Significant differences between the 'fertile' and the 'subfertile' group were found for all of the evaluated sperm quality parameters (except for BCF, LIN, STR and MEDIUM). In conclusion, dogs tend to produce ejaculates with a lower percentage of normal spermatozoa with increasing age and dogs with higher body weights produce ejaculates with a higher TSO and a lower VCL. Significantly poorer sperm characteristics were found for dogs with lower in vivo fertility results.

A computerized spectrophotometric instrumental system to determine the “vertical velocity” of sperm cells: A novel concept

BACKGROUND

The presently available cell motility-analyzers measure primarily the "horizontal" velocity and there is no instrument available for "vertical" velocity measurement. This development was based on the turbidimetric method of sperm motility analysis.

METHODS

Sperm was layered at the bottom of the cuvette containing buffer solution and exposed to the spectrophotometric light path at different heights to track the vertically moving sperms. The vertical movement was materialized with the development of an electromechanical up-down movement devise for the cuvette accomplished with the help of a cuvette holder-stepper motor-computer assembly. The entire system was controlled by the necessary motion control, data acquisition, and data processing software developed for cuvette movement and data analysis.

RESULTS

Using goat sperm as the model a unique computer-based spectrophotometric system has been developed for the first time to determine the average "vertical" velocity of motile cells.

CONCLUSIONS

Undertaking upward movement against gravity is much tougher as compared with horizontal movement. Consequently average vertical velocity is expected to be a much better identifying parameter for assessing semen and other motile cell quality. The novel instrumental system developed by us has thus the potential for immense application in human infertility clinics, animal-breeding centres, centres for conservation of endangered species, and also for research work on vertical velocity of spermatozoa and other motile cells, such as bacteria, protozoa, etc.

Measuring mouse sperm parameters using a particle counter and sperm quality analyzer: A simple and inexpensive method

This study examined a method for analyzing the count, motility, and morphology of mouse epididymal sperm, optimizing the diluent, incubation time, sample concentration, and temperature, using a particle counter (CDA-500) to count and size sperm and a sperm quality analyzer (SQA-IIC) to measure sperm motility, quantified as the sperm motility index (SMI). The optimal conditions consisted of a 30-min incubation in D-MEM (Dulbecco's modified Eagle's medium; considering cost and availability) at 37 degrees C, with 5 x 10(6)cells mL(-1) in the original solution. Furthermore, the influence of formalin fixation, and the correlation between the automated counter and a manual method were investigated. The sample fixation had no marked effect on the sperm count or morphology assessment. A linear correlation was observed between the manual and automated methods (y=0.920x +0.276; r(2)=0.571; p<0.001; range: (3-6) x 10(6)). The suitability of the proposed method was confirmed using spermatozoa prepared from mice treated with the reproductive toxin diethylstilbestrol (DES). Using sperm from the cauda epididymidis on one side per mouse, we confirmed that measurement of these sperm parameters using the two devices was simple, rapid, inexpensive, and reproducible.

The immediate impact of semen diluent and rate of dilution on the sperm quality index, ATP utilization, gas exchange, and ionic balance of broiler breeder sperm

The sperm quality index (SQI) is a tool used to predict overall rooster semen quality, fertility, and hatchability. However, semen must be diluted before SQI analysis, and research has shown that the SQI is most predictive of fertility at lower semen dilutions. Therefore, the present study was undertaken to determine why the SQI is not as predictive of fertility at higher semen dilutions and whether semen diluent type alters the SQI, adenosine triphosphate (ATP) utilization, gas exchange, and ionic balance of broiler breeder sperm. Semen was diluted with saline, seminal plasma, or minimum essential medium (MEM) from 2- to 200-fold. The following parameters were measured for each diluent type at each dilution: SQI, ATP, Na+, Ca2+, K+, Cl-, CO2, and O2. To examine the rate of sperm motility, the SQI was expressed as SQI/million sperm per mL (SQI/sperm). There was an interaction between diluent type and dilution for the SQI, SQI/sperm, CO2 generated, O2 used, as well as Na+, Ca2+, and K+ internalization. For sperm diluted with saline, the SQI declined more rapidly with increasing dilution. However, SQI/sperm increased rapidly when semen was diluted with MEM or SP. Sperm diluted in SP used ATP with increasing dilution whereas sperm diluted with saline and MEM generated ATP. Neat semen contained no free O2; however, each diluent type contained abundant O2 resulting in more O2 available as semen was diluted. Sperm diluted in SP produced more CO2 and used more O2 than semen diluted in saline or MEM. For SQI/sperm, ATP and CO2 generated, as well as Na+ and Ca2+ internalization, differences between diluent types occurred when semen was diluted 50-fold and greater. In conclusion, it appears that sperm motility, ATP utilization, gas exchange, and ionic balance are altered by diluent type and rate of dilution. These alterations in semen quality are exacerbated at semen dilutions of 50-fold and greater yielding an SQI that is not indicative of sperm motility or fertility.

New techniques for the assessment of canine semen quality: A review

Until recently, canine semen assessment was routinely performed by conventional light microscopic techniques. The limitations of these methods include subjectivity, variability, the small number of spermatozoa analyzed, and poor correlation with fertilizing potential. The last decade, several new in vitro techniques have been introduced for canine semen assessment that enable a more detailed evaluation of several sperm characteristics. Numerous fluorescent staining techniques have been developed for the evaluation of specific sperm characteristics and functions, including plasma membrane integrity, capacitation status and the acrosome reaction. By combining fluorescent stains, several functional sperm characteristics can be assessed simultaneously. Moreover, by means of flow cytometry, large numbers of fluorescently labelled spermatozoa can be analysed in a short interval. Following thorough standardization and validation, computer-assisted sperm analysis systems provide objective and detailed information on various motility characteristics and morphometric dimensions that cannot be identified by conventional light microscopic semen analysis. In vitro assays, evaluating the capacity of canine spermatozoa to bind to the zona pellucida or oviductal explants, or to penetrate the oocyte, provide additional information on canine gamete interaction that may be useful in predicting the fertilizing potential of spermatozoa. Although substantial improvements have been made in canine semen assessment, surprisingly few parameters were correlated with in vivo fertility. Therefore, further research is required to determine which sperm characteristics are of clinical value for predicting the in vivo fertility in dogs.

Validation and Usefulness of the Sperm Quality Analyzer (SQA II-C) for Bull Semen Analysis

In this study, an upgrade version of the Sperm Quality Analyzer (SQA), the SQA-IIC was tested for the assessment of bull semen quality. In Expt 1, the device showed good repeatability of measurements within and between capillaries, as evidenced by the low coefficients of variation (CVs; < 13%) at concentrations between 35 and 705 x 10(6) spermatozoa/ml. In Expt 2, 10 semen concentrations (1-1000 x 10(6)/ml) were stored in HEPES TALP for 48 h at room temperature. A time-dependent decrease in sperm motility index (SMI) values was noticed. SMI values increased linearly with increasing sperm concentrations, but remained constant around 500, corresponding to a concentration of approximately 50 x 10(6)/ml. For sperm concentrations below 50 x 10(6)/ml, SMI values were highly correlated with concentration (p < 0.05) and with semen parameters, expressing the overall semen quality (p < 0.05; Expt 3). In Expt 4, a correlation of only 0.44 (p < 0.05) between SMI values of frozen-thawed semen samples of 35 bulls and the corrected 56-day non-return rate (56dNRRc) was found. Prediction of the 56dNRRc based on the SMI value of a semen sample was inaccurate. The present study indicates that the SQA-IIC is suitable for a rapid screening of bull semen diluted to a concentration of approximately 50 x 10(6)/ml. Furthermore, the device seems inappropriate for fertility prediction.

Effect of 655-nm diode laser on dog sperm motility

Sperm motility depends on energy consumption. Low-level laser irradiation increases adenosin triphosphate (ATP) production and energy supply to the cell. The aim of this study is to analyse whether the irradiation affects the parameters that characterise dog sperm motility. Fresh dog sperm samples were divided into four groups and irradiated with a 655-nm continuous-wave diode laser with varying doses: 0 (control), 4, 6 and 10 J/cm(2). At 0, 15 and 45 min following irradiation, pictures were taken of all the groups in order to study motility with computer-aided sperm analysis (CASA). Functional tests were also performed. Average path velocity (VAP), linear coefficient (Lin) and beat cross frequency (BCF) were statistically and significantly different when compared to the control. The functional tests also showed a significant difference. At these parameters, the 655-nm continuous-wave diode laser improves the speed and linear coefficient of the sperm.

Motility Assessment of Porcine Spermatozoa: a Comparison of Methods

Although widely used in practice, visual motility assessment of boar spermatozoa is a very subjective method. The aim of this study was to compare the visual motility assessment of boar spermatozoa with two objective, automated systems, namely the Sperm Quality Analyzer (SQA-IIC) and the Hamilton-Thorne computer-based semen analyzer (HTR). In addition, concentrations as determined by the Burker counting chamber and HTR were compared. Motility of 30 semen samples from 30 different boars (22 Pietrain, seven Landrace boars and one Large White) was examined during three consecutive days, subjectively by two independent persons (visual motility assessment) and objectively with both automated systems. The use of the SQA-IIC and HTR for assessing boar sperm motility was evaluated and the repeatability of the measurements was estimated. The Sperm Motility Index (SMI), determined by SQA-IIC, and the percentage motile spermatozoa determined by the HTR showed a good correlation (r=0.71; p <0.05). The visual examination performed by Person 2 showed a good correlation with the SMI (r=0.81) and with the percentage of motile spermatozoa measured by the HTR (r=0.66) (p <0.05). There was a very poor correlation and a limited agreement between the visual assessments of both persons emphasizing the subjectivity of visual motility assessment. Nevertheless, motility scores of each person during the three consecutive days were highly correlated (r=0.67 and 0.72, p <0.05). The limits of agreement plots showed poor agreement between both persons and the HTR. The repeatability of measurements for most parameters evaluated by the HTR and by the SQA-IIC was good with coefficients of variation below 10%. In addition, for fertile Pietrain boars (n=22), reference values for the different HTR-parameters are presented showing a high curvilinear velocity (157.3 +/- 19.5 microm/s) and a low straightness and linearity of the movement of the spermatozoa (62.7 +/- 8.7 and 35.5 +/- 7.6%, respectively). Concentration as determined by the Burker counting chamber (56.0 +/- 16.8 x 10(6)/ml) was significantly higher compared with HTR measurement (37.6 +/- 7.7 x 10(6)/ml). The high number of counted cells and the low variation render the HTR concentration measurement more reliable. It can be concluded that visual motility assessment is highly subjective and should therefore be replaced by automated systems that allow for a more objective and detailed motility assessment of boar spermatozoa. In addition, based on the present results, highly repeatable results were obtained by the SQA-IIC and especially by the HTR.

Validation of the Sperm Quality Analyzer and the Hypo-osmotic Swelling Test for Frozen-thawed Ram and Minke Whale (Balaenoptera bonarensis) Spermatozoa

The object of the present study was to investigate the validation of the sperm quality analyzer (SQA) and the hypo-osmotic swelling (HOS) test with standard sperm analysis methods in frozen-thawed ram and minke whale spermatozoa. In rams, highly significant correlations were observed in the percentage of motile spermatozoa (P<0.01) and sperm concentration (P<0.01) between the standard and SQA methods. But, the percentage of morphologically normal spermatozoa did not significantly correlate between the standard and SQA methods. The percentages of swollen spermatozoa at 15 minutes by the HOS test were significantly correlated with the motility by the standard (P<0.05) and by the SQA (P<0.05) methods. For minke whale spermatozoa, the SVI (sperm viability index) values by the standard method were significantly (P<0.001) correlated with the sperm motility index (SMI) values by SQA. The percentage of motile spermatozoa was also significantly correlated (P<0.01) with the motility measured by SQA. Using different hypo-osmotic solutions and incubation times, the HOS test with 25, 100 and 150 mOsM did not show significant variations. Motility observed by the standard method and the percentage of swollen spermatozoa were significantly correlated (P<0.05). These results indicate that the SQA and HOS test can be utilized to assess the post-thawing motility of ram and minke whale spermatozoa, and that the SQA and HOS test values are significantly correlated in ram spermatozoa. However, sperm concentration and morphologically normal spermatozoa are not assessed accurately by SQA in minke whales.

Motility characteristics of boar spermatozoa after addition of prostaglandin F2alpha

Addition of prostaglandin F2alpha (PGF2alpha) to extended boar semen has been shown to slightly increase reproductive parameters in sows such as the conception rate and the total number of piglets born alive. The mechanisms by which PGF2alpha affect these parameters have not yet been elucidated, but it is possible that the sperm transport after insemination is increased. This study investigated whether the sperm motility from 20 Piétrain boars improved when PGF2alpha (Dinolytic; 5 mg PGF2alpha/ml) was added to diluted semen. Different amounts of PGF2alpha (0, 0.5, 1 and 2 ml/100 ml) were tested and the motility was evaluated immediately after addition of PGF2alpha, after 30 min, 2 h, and 24 h. Two computer-assisted semen analysis (CASA) systems, namely the Sperm Quality Analyzer (SQA-IIC) and the Hamilton Thorne (HTR Ceros 12.1) were used to assess the motility parameters. With the SQA-IIC, sperm motility index values of the treated groups were only slightly higher (P>0.05) compared to the negative control group. The different motility parameters measured with the HTR Ceros 12.1 were similar between the treatment groups, except for beat cross frequency, which was higher in the control group (1.5-5%; P<0.001). This study documented that the addition of 2.5, 5 or 10 mg PGF2alpha to 100 ml diluted boar sperm does not increase any sperm motility parameter. Further research is necessary to elucidate mechanisms by which PGF2alpha in diluted semen may improve the reproductive performance in swine farms.

Semen dilution prior to analysis influences the ability of the sperm quality analyzer to predict fertility whether inseminating with a constant number of sperm or a constant volume of semen

Previous research has shown that the sperm quality index (SQI) is positively correlated with semen characteristics as well as fertility when broiler breeder semen is diluted 10-fold prior to analysis. However, research has not been conducted to establish if semen dilution rate affects the ability of the SQI to predict fertility when inseminating a constant number of sperm or a constant volume of semen. As a result, 3 experiments were undertaken. The objective of the first study was to determine if diluent, minimum essential media, or 0.85% saline affects the SQI. The second objective was to identify potential semen dilution rates for the SQI by obtaining the range in live sperm concentrations to which the SQI is most sensitive. The purpose of experiment 3 was to determine which semen dilution rate, 10-, 25-, 50-, 75-fold, or a constant concentration of 180 x 10(6) sperm/mL, yields an SQI that is most predictive of fertility. Once a week for 3 wk, 20 hens were individually inseminated with either 20 microL of 4-fold diluted semen or a constant 45 x 10(6) sperm from each of 29 broiler breeder males. To determine which semen dilution rate yielded an SQI that was most predictive of fertility, Pearson's correlation coefficients were obtained between the SQI at each dilution rate and fertility. There was no difference in the SQI due to diluent. Sperm quality index values declined logarithmically as live sperm concentration decreased. The SQI was most sensitive to live sperm concentrations from 11 to 232 x 10(6) sperm/mL. The SQI for semen diluted 10-fold was the best predictor of fertility when inseminating with a constant volume of 4-fold diluted semen (r = 0.71). When hens were inseminated with a constant 45 x 10(6) sperm/hen, the SQI for semen diluted 10- and 25-fold as well as to a constant concentration of 180 x 10(6) sperm/ mL was equally effective at predicting fertility (r = 0.59, 0.52, and 0.61, respectively). Apparently, the SQI is predictive of fertility when semen samples are diluted 10-fold prior to analysis regardless of insemination method used. Dilution beyond 10-fold appears to alter semen quality, rendering the SQI less accurate.

Effect of technical settings on canine semen motility parameters measured by the Hamilton-Thorne analyzer

Computerized measuring devices are needed to assess canine semen quality objectively both for research and practical purposes. As internal image settings may influence the results considerably, the effect of different technical settings and semen processing on the parameters assessed by the Hamilton-Thorne Ceros 12.1 semen analyzer (HTR Ceros 12.1) was investigated. The frame rate (15, 30 or 60 frames/s) significantly (P<0.05) influenced most of the measured motility characteristics in experiment 1 while no differences in the motility parameters were found using a different sampling duration (0.5 or 1 s, i.e. 30 or 60 frames scanned) in experiment 2. In experiment 3, an increase in sperm velocity (VAP, VSL, VCL), in linearity and in the percentage of motile and rapidly moving spermatozoa was observed with increasing sperm concentrations (25 x 10(6), 50 x 10(6) or 100 x 10(6) ml(-1)). In experiment 4, a clear effect of the diluent used was visible with higher velocity parameters (VAP, VSL, VCL) and higher percentages of motile, progressive and rapid spermatozoa for semen samples diluted in Hepes-TALP or prostatic fluid in comparison with physiological saline or egg-yolk-Tris extender. In experiment 5, significant (P<0.01) and high correlations were found between the conventional dog semen analysis methods and HTR Ceros 12.1 measurements (n=97 semen samples) for the sperm concentration (r=0.91), the motility (r=0.74) and the progressive motility (r=0.84). In experiment 6, the ejaculates from 21 proven, fertile dogs were compared with the ejaculates of a population (N: 11) of young beagles (1.5 years) but no significant differences in HTR Ceros 12.1 measurements were found between the two groups. Based on our results, diluting dog semen samples to 50 x 10(6) ml(-1) with physiological saline solution and scanning 30 frames at a frame rate of 60 frames/s (i.e. a scanning time of 0.5 s), are the set-up parameters proposed to obtain objective and standardized canine semen motility results using the HTR Ceros 12.1.

Comparison of the BullMate sperm quality analyzer with conventional means of assessing the semen quality and breeding soundness of beef bulls

An instrument called the Optibreed, BullMate sperm quality analyzer (SQA) contains a densitometer for determining sperm cell concentration and an optical sensor to evaluate light deflections caused by sperm movement. Analysis of light deflections enables the generation of a value called the sperm quality index (SQI). The SQI represents the quality of a semen sample defined by sperm motility, concentration, viability and morphology. The SQA was compared to conventional, microscopic techniques for determining percent motile sperm and sperm concentration in bull semen samples and evaluated for its ability to classify bulls as satisfactory or unsatisfactory potential breeders. Semen samples were collected from 105 mature beef bulls by electroejaculation (day 1) and from 51 of the same bulls by internal artificial vagina (IAV) on day 2. SQI values were arranged into 20 categories in increments of 50units from 0 to 1000units. Percent motile sperm and sperm concentration values from both methods were significantly positively correlated (P<0.000) with respective r values of 0.82 and 0.80. A calculation of kappa to evaluate the differences in percent motile sperm generated by each system yielded a value of 0.20 and 0.54 for unweighted and weighted determinations, respectively. The intraclass correlation coefficient used to evaluate the reliability of sperm cell concentration determinations was 0.62 (P<0.05). SQI values generated on days 1 and 2 ranged from 0-994 to 0-906, respectively. Bulls were categorized as satisfactory or unsatisfactory potential breeders in all categories. The most appropriate SQI for determining whether a bull was a satisfactory or unsatisfactory potential breeder was 500 with respective sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) of 81, 65, 90.79 and 44.83%. In this experiment the BullMate SQA was not a reliable substitute for conventional semen analysis and was not useful for determining bull breeding soundness.

Use of the Sperm Quality Analyzer (SQA II-C) for the assessment of dog sperm quality

In the present study, an automated system for sperm analysis, the Sperm Quality Analyzer (SQA II-C), was tested as a potential tool for the assessment of dog sperm quality. In the first experiment the device displayed a good repeatability of measurements for semen of medium and high quality, as evidenced by a low coefficient of variance (CV; 0.08), whereas a high CV (0.46) was obtained for one dog with semen of inferior quality. In the second experiment, seven different sperm concentrations (25-300 x 106/ml), obtained by dilutions in Hepes-TALP medium were stored for 48 h at room temperature. A concentration dependent increase in sperm motility index (SMI) was shown, reaching a plateau at 150 x 106 spermatozoa/ml. For all sperm concentrations, the SMI value decreased significantly after 24 h, indicating the importance of sperm motility for SMI values. For sperm concentrations lower than 150x106/ml, highly significant correlations [r=0.80;p<0.05] were established between SMI values on one hand and sperm concentration, and semen parameters expressing the overall semen sample quality on the other hand (experiment 3) while non-significant or low correlations were found between SMI values and other individual sperm parameters. In experiment 4, significantly high correlations (r=0.97) were found between mean SMI values and post-thaw motility and progressive motility assessed subjectively. In conclusion, our study indicates that both motility and concentration largely influence SMI values and that the SQA II-C saturates at 150 x 106 fresh spermatozoa/ml. In our opinion, the SQA II-C may be a useful and objective device to assess the post-thaw motility of dog sperm.