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The semen movement and sperm head size patterns of boar ejaculates were analyzed using computer-assisted semen analysis (CASA)-Mot and -Morph systems. The aim of the present study was to compare morphometric and kinematics variables from boars and to determine the relationship with sow fertility variables related to litter size. The females were from maternal crossing schemes such as the continuous 3-generation cross between York (Y), Landrace (L), and Pietrain (P) hybrid sows and Pietrain boars. Semen samples were collected from 11 sexually mature boars from two sire lines. Samples were analyzed using the ISAS® v1 system to evaluate eight kinematic variables of sperm velocity, progressiveness and undulations. Four morphometric parameters of sperm head size (length, width, area, and perimeter) were analyzed. Bayesian analysis revealed relevant differences in four kinematic variables (VSL, LIN, STR, and WOB) between sire lines, with a probability of relevance (PR ) of 0.79-0.91, and Pietrain boars were associated with higher progressive motility compared with Duroc x Pietrain boars. Moreover, there were relevant differences in all morphometric variables (PR = 0.82-0.85) between sire lines. The dam line Y-L-50 (½ Y x ½ L) had higher total born per litter and piglets born alive, and YLP-75 (1 /8 Y x 1 /8 L x 3 /4 P) was associated with higher values of litter weight at birth (highest posterior density region at 95% = 9.92, 16.41 kg). There are relevant differences in kinematic variables between the assessed sire lines and the differences in morphometric and litter size variables were also relevant. The York-Landrace hybrid sows had higher total born per litter and piglets born alive, and there were relevant differences when compared with YLP-50 (¼ York x ¼ Landrace x ½ Pietrain). Differences in kinematic and morphometric variables between sire and dam lines related to fertility need to be further studied.

The aim was to determine the relationship between kinematic parameters of boar spermatozoa and fertility rates of sow, as well as to assess the effect of sperm clusters on the fertility capacity of the ejaculate. Semen samples were collected from 11 sexually mature boars. Samples were analyzed by an ISAS®v1 CASA-Mot system for eight kinematic parameters. Ejaculate clusters were characterized using multivariate procedures, such as principal factors (PFs) analysis and clustering methods (the k-means model). Four different ejaculate clusters were identified from two kinematic PFs which involved linear trajectory and velocity. There were differences (p < 0.05) between the sperm kinematic variables by sire line. There was no statistical difference (p > 0.05) between dam lines and ejaculate clusters in fertility variables. The discriminant ability of the different kinematics of sperm variables to predict litter size fertility was analyzed using receiver operating characteristics (ROC) curve analysis. Curvilinear velocity (VCL), average path velocity (VAP), amplitude of lateral head displacement (ALH), and beat-cross frequency (BCF) showed significant, albeit limited, predictive capacity for litter size fertility variables (range: 0.55–0.58 area under curve, AUC). The kinematic analysis of the ejaculates in clusters did not have a predictive capacity for litter size variables., This research was funded by Fundación para el Fomento y Promoción de la Investigación y Transferencia de Tecnología Agropecuaria de Costa Rica (FITTACORI), grant number F23-19 and the Costa Rica Institute of Technology (Vice-Chancellor’s office of Research and Extension; VIE (Vicerrectoría de investigación y Extensión; Project-VIE-5402-2151-1015).

Computer Assisted Semen Analysis (CASA) technology is being a common tool in the seminal analysis for seminal doses production in farm animals. The aim of the present work was to define the optimal capturing time for a correct evaluation of boar sperm motility. Six sexually mature boars from the Topigs Lines, were used as semen donors. ISASv1 CASA-Mot system was used with an image acquisition rate of 50 Hz for two seconds capturing. Obtained video frames were fragmented into four segments corresponding to 0.5, 1.0, 1.5 and 2.0 s. ISASD4C20 counting chambers, warmed at 37 °C were used. Total and progressive motility were not affected by capture time. Capture time had a significant effect on velocity and indexes values (P

This study was conducted to determine optimum image capture frame rates (FRO) when there was evaluation of different types of counting chambers used for CASA-Mot determinations of stallion sperm motility. Sperm VCL was determined at frame rates of 25-250 f/s in: 1) Spermtrack® (Spk) 10 and 20 chambers (drop displacement-type chambers 10 and 20 μm-deep respectively; and 2) ISAS®D4C10, ISAS®D4C20 (10 and 20 μm-deep respectively) and ISAS®D4C20 L (20 μm-deep) capillary loaded chambers. Values for different sperm kinematic variables were determined using each chamber at 250 f/s, which is the maximum frame rate that the software can be used for analyses. With evaluation of Spk chambers, there was a greater curvilinear velocity (VCL), average path velocity (VAP), straight line velocity (STR), amplitude of lateral head displacement (ALH) and beat cross frequency (BCF) values (P 0.05) than with capillary loaded chambers, with there being greatest values with 20 μm-deep chambers. With the Spk10 chamber, VCL and ALH were greater at the chamber centre than periphery. There were no such differences for the Spk20 chamber. With evaluation of the D4C10 chamber, VSL and STR were less when there was a sperm deposition point towards the chamber end, while there were the opposite for the D4C20 chamber. When there was evaluation of the D4C20 chamber, there were also greater VCL, WOB and BCF values in distal areas. With use of most of these chambers, data should be collected from different fields and means determined, however, this is not necessary with Spk20 chambers.

In order to optimize the donkey sperm motility analysis by the CASA (Computer Assisted Sperm Analysis)-Mot system, twelve ejaculates were collected from six jackasses. Capillary loaded chamber (CLC), ISAS&reg, D4C depths 10 and 20 &micro, m, ISAS&reg, D4C Leja 20 and drop displacement chamber (DDC), Spermtrack&reg, (Spk) depths 10 and 20 &micro, m were used. Sperm kinematic variables were evaluated using each chamber and a high-resolution camera capable of capturing a maximum of 500 frames/second (fps). The optimum frame rate (OFR) (defined according to curvilinear velocity&mdash, VCL) was dependent on chamber type. The highest OFR obtained was 278.46 fps by Spk20. Values for VCL, straight-line velocity (VSL), straightness (STR), amplitude of lateral head displacement (ALH) and beat cross frequency (BCF) were high in DDC and 10 &micro, m depth. In both DDC 10 and 20 &micro, m, the sperm velocities (VCL, VSL, VAP) and ALH values decreased significantly from the centre to the edges, while Wobble and BCF increased. No defined behavior was observed along the CLC. However, all the kinematic variables had a higher value in a highly concentrated sample, in both chamber types. In conclusion, analyzing a minimum of nine fields at 250 fps from the centre to the edges in Spk10 chamber using a dilution of 30 &times, 106 sperm/mL offers the best choice for donkey computerised sperm motility analysis.

The ejaculate is heterogenous and sperm sub-populations with different kinematic patterns can be identified in various species. Nevertheless, although these sub-populations are statistically well defined, the statistical differences are not always relevant. The aim of the present study was to characterize kinematic sub-populations in sperm from two bovine species, and diluted with different commercial extenders, and to determine the statistical relevance of sub-populations through Bayesian analysis. Semen from 10 bulls was evaluated after thawing. An ISAS&reg, v1 computer-assisted sperm analysis (CASA)-Mot system was employed with an image acquisition rate of 50 Hz and ISAS&reg, D4C20 counting chambers. Sub-populations of motile spermatozoa were characterized using multivariate procedures such as principal components (PCs) analysis and clustering methods (k-means model). Four different sperm sub-populations were identified from three PCs that involved progressiveness, velocity, and cell undulatory movement. The proportions of the different sperm sub-populations varied with the extender used and in the two species. Despite a statistical difference (p &lt, 0.05) between extenders, the Bayesian analysis confirmed that only one of them (Triladyl&reg, ) presented relevant differences in kinematic patterns when compared with Tris-EY and OptiXcell&reg, Extenders differed in the proportion of sperm cells in each of the kinematic sub-populations. Similar patterns were identified in Bos taurus and Bos indicus. Bayesian results indicate that sub-populations SP1, SP2, and SP3 were different for PC criteria and these differences were relevant. For velocity, linearity, and progressiveness, the SP4 did not show a relevant difference regarding the other sperm sub-populations. The classical approach of clustering or sperm subpopulation thus may not have a direct biological meaning. Therefore, the biological relevance of sperm sub-populations needs to be reevaluated.

This work provides information on the blue fox ejaculated sperm quality needed for seminal dose calculations. Twenty semen samples, obtained by masturbation, were analyzed for kinematic and morphometric parameters by using CASA-Mot and CASA-Morph system and principal component (PC) analysis. For motility, eight kinematic parameters were evaluated, which were reduced to PC1, related to linear variables, and PC2, related to oscillatory movement. The whole population was divided into three independent subpopulations: SP1, fast cells with linear movement; SP2, slow cells and nonoscillatory motility; and SP3, medium speed cells and oscillatory movement. In almost all cases, the subpopulation distribution by animal was significantly different. Head morphology analysis generated four size and four shape parameters, which were reduced to PC1, related to size, and PC2, related to shape of the cells. Three morphometric subpopulations existed: SP1: large oval cells; SP2: medium size elongated cells; and SP3: small and short cells. The subpopulation distribution differed between animals. Combining the kinematic and morphometric datasets produced PC1, related to morphometric parameters, and PC2, related to kinematics, which generated four sperm subpopulations - SP1: high oscillatory motility, large and short heads; SP2: medium velocity with small and short heads; SP3: slow motion small and elongated cells; and SP4: high linear speed and large elongated cells. Subpopulation distribution was different in all animals. The establishment of sperm subpopulations from kinematic, morphometric, and combined variables not only improves the well-defined fox semen characteristics and offers a good conceptual basis for fertility and sperm preservation techniques in this species, but also opens the door to use this approach in other species, included humans.

Semen quality assessment requires accurate, reliable and objective methods for examination of sperm variables including sperm motility. For preparation of semen samples for artificial insemination, as a genetic resource, samples that are used for insemination need to have the capacity to result in a highly acceptable fertility rate. Several methods have been developed for evaluation of bull sperm in laboratory conditions and for preparation of doses for artificial insemination. Computer-assisted semen analyses can provide objective information on various sperm variables. Nevertheless, this equipment requires fine-calibrations considering differences among species, breeds and conditions for sample evaluation and data analyses. In the present study, there was examination of the interaction between factors such as image frame rate and type and depth of counting chamber in which sperm were evaluated, together with differences between bulls of four breeds. The use of the Spermtrack® reusable 10 μm-depth chamber provided more reliable results than results obtained using disposable chambers (10 and 20 μm depth). A capture rate of at least 90 fps is required for assessment of sperm motility percentage, whereas a rate of 250 fps is needed for obtaining consistent kinematic data. Differences among breeds in the present study indicate conditions for sperm analyses should include specific equipment calibrations for each breed. These results contribute to development of more precise conditions for assessments of bull sperm quality taking into account breed differences and the requirement each breed has for the adequate evaluation and preparation of samples for artificial insemination., DB received a grant from MINECO, Spain (Grant AGL2014-52775-P). AV was the recipient of a grant from CONICIT and MICITT ,Costa Rica. ERSR was supported by funds from MCIU, Spain.

Resumen Introducción. La comprensión de la variabilidad en los valores de la cinética de los espermatozoides, por medio de diferentes profundidades de cámaras, demuestra la importancia de crear un estándar para los métodos de control de calidad en la industria de la inseminación artificial (IA). Objetivo. El objetivo del presente trabajo fue evaluar los parámetros de cinética de los espermatozoides con base en diferentes profundidades de cámara de visualización mediante un sistema comercial de análisis de esperma asistidos por computadora, CASA-Mot. Materiales y Métodos. Se utilizaron veinte dosis seminales de diez verracos pietrain. El periodo experimental fue de febrero a julio del año 2017. Se utilizó el sistema integrado de análisis de semen (ISAS®v1) con una frecuencia de captura de 50 Hz. Se utilizaron cámaras de recuento ISAS®D4C16 e ISAS®D4C20 con una altura de 16 y 20 μm, respectivamente y precalentadas a 37 °C. Resultados. Se encontraron valores superiores (p

The development of analytical methods for the evaluation of crocodilian semen is an important component for the assessment of male breeding soundness and the development of assisted breeding technology in this taxon. Computer-Assisted Semen Analysis (CASA) technology is becoming an increasingly common technique in seminal evaluations for animals but there has been no application of this technique for reptilian spermatozoa. The aim of this study was to analyse sperm kinematic and morphometric variables in Caiman crocodilus fuscus semen samples and to determine whether there were sperm subpopulations. Four ejaculates from four sexually mature captive caimans were used for this study. A CASA-Mot and CASA-Morph system was used with an image acquisition rate of 50 Hz for 2 s of capture. The ISAS®D4C20 counting chambers were used and spermatozoa incubated at 25 °C. Total and progressive motilities did not differ among animals (P > 0.05). There was a significant animal effect in the model with respect to sperm morphometry, and kinematic indices including linearity (LIN) and straightness (STR) (P

[EN] It is essential to define an optimized standard method to assess the fish sperm quality to minimize the differences between the results obtained by different laboratories. Only this optimization and standardization can make them useful from academia to industry. This study presents the validation of sperm motility assessment using a CASA-Mot system for three endangered diadromous fish species: European eel (Anguilla anguilla), Atlantic salmon (Salmo salar) and Siberian sturgeon (Acipenser baerii). To attain this goal, different technical and data processing methods were tested: 1) magnification lens (×10 and ×20), 2) Spermtrack® reusable chambers (10 and 20¿¿m depth) and 3) different frame rates (50¿¿¿FR¿¿¿250). The results suggested that the sperm motility assessment for eel, salmon and sturgeon should be performed at 200, 250 and 225¿frames¿s¿1, respectively. Moreover, to obtain a high number of analysed spermatozoa in less time and a natural movement of the sperm cells, it is recommended to use ×10 objective and 20¿¿m depth. In conclusion, different technical settings influence sperm kinetic parameters and should be validated for each fish species to allow the comparison of results between laboratories., This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No [642893]. AV is granted by the CONICIT and MICITT, Costa Rica. The study was financially supported by the Ministry of Education, Youth and Sports of the Czech Republic projects "CENAKVA" (No. CZ.1.05/2.1.00/01.0024), "CENAKVA II" (No. LO1205 under the NPU I program), project Biodiversity (CZ.02.1.01/0.0/0.0/16_025/0007370), by the Czech Science Foundation (project No. 17-19714Y).

The aim of the study was to compare the morphometric features of sperm head sizeand shape from the Pietrain line and the Duroc×Pietrain boar crossbred terminal lines, and toevaluate their relationship with reproductive success after artificial insemination of sows producedfrom crossbreeding the York, Landrace and Pietrain breeds. Semen samples were collected from 11sexually mature boars. Only ejaculates with greater than 70% motility rate and, This research was funded by the Fundación para el Fomento y Promoción de la Investigación y Transferencia de Tecnología Agropecuaria de Costa Rica (FITTACORI) and the Costa RicaInstitute of Technology (Vice-Chancellor’s office of Research and Extension; VIE (Vicerrectoría de investigación y Extensión); Project 5402-2151-1015

Artículo científico Sperm quality is evaluated for the calculation of sperm dosage in artificial reproductive programs. The most common parameter used is motility, but morphology has a higher potential as a predictor of genetic quality. Morphometry calculations from CASA‑Morph technology improve morphological evaluation and allow mathematical approaches to the problem. Semen from 28 Holstein bulls was collected by artificial vagina, and several ejaculates were studied. After general evaluation, samples were diluted, packaged in 0.25 ml straws, and stored in liquid nitrogen. Two straws per sample were thawed, and slides were processed and stained with Diff‑Quik. Samples were analyzed by a CASA‑Morph system for eight morphometric parameters. In addition to the “classical” statistical approach, based on variance analysis (revealing differences between animals, ejaculates, and straws), principal component (PC) analysis showed that the variables were grouped into PC1, related to size, and PC2 to shape. Subpopulation structure analysis showed four groups, namely, big, small, short, and narrow from their dominant characteristics, representing 31.0%, 27.3%, 24.1%, and 17.7% of the total population, respectively. The distributions varied between animals and ejaculates, but between straws, there were no differences in only four animals. This modern approach of considering an ejaculate sperm population as divided into subpopulations reflecting quantifiable parameters generated by CASA‑Morph systems technology opens a new view on sperm function. This is the first study applying this approach to evaluate different ejaculates and straws from the same individual. More work must be done to improve seminal dose calculations in assisted reproductive programs. Instituto Tecnológico de Costa Rica. Escuela de Agronomía. Sede San Carlos.

Resumen La evaluación de la calidad seminal constituye una herramienta para mejorar los índices reproductivos en las granjas porcinas. La movilidad del espermatozoide es un parámetro que se utiliza en la evaluación de la calidad espermática, porque se relaciona con el nivel de energía del gameto masculino. El objetivo de este estudio fue determinar la influencia de la composición racial sobre variables reproductivas de calidad, cinética y movilidad del semen en verracos. Durante el año 2016, se recolectaron 240 eyaculados de 63 verracos con una edad media de 24,4±10,9 meses. Se identificaron seis grupos raciales: Duroc (D), Yorkshire (Y), Landrace (L), F1 Pietrain*Duroc (PD) y dos líneas genéticas (LA y LB). Los grupos raciales con mayor volumen de eyaculado presentaron un número total de espermatozoides más elevado (P

Motility is the most widely used indicator of sperm quality. Computer-Assisted Semen Analysis (CASA) allows the objective evaluation of sperm motility parameters. CASA technology is a common tool to predict semen doses in farm animal reproduction. The kinds of video cameras used until now for image acquisition have presented limited frame rates (FR), which have a negative influence on the quality of the obtained data. The aim of the present work was to define the optimal frame rate for a correct evaluation of boar sperm motility and its subpopulation structure. Eighteen ejaculates from nine mature boars of the Pietrain breed were used. Using the ISAS® v1 CASA-Mot system, with a video camera working up to 200 Hz, six FRs (25, 50, 75, 100, 150 and 200 fps) were compared. ISAS® D4C20 counting chambers, warmed to 37°C, were used. FR affected all the kinematic parameters, with curvilinear velocity (VCL) and BCF the most sensitive ones. All the parameters showed differences among animals. Non-linear correlation showed the asymptotic level for VCL at 212 fps, being the highest FR for all the parameters. For future studies based just on progressive motility, almost 100 fps FR for 0.5 s must be used, while when kinematics must be considered, almost 212 fps for one-second should be analysed. Three principal components were obtained (velocity, progressivity and oscillation), being similar at 50 and 200 fps. Cells were grouped in four subpopulations but with different kinematic and cellular distribution at both FRs.

Semen analysis is a key factor when determining the fertility ability in males. South American camelids, and in particular the alpaca, have been studied very little when compared with other farm animals. The aim of this work was to perform the kinematic characterization of alpaca spermatozoa collected directly from the deferent duct by using CASA-Mot (Computer Assisted Semen Analysis for Motility) technology. Samples were obtained every three days throughout the reproductive season during two periods and with a break of seven days in the middle. During both periods, the quality of the sample's motility and kinematics increased over the first two days and then subsequently decreased. This pattern was similar in all animals. It was concluded that the introduction of resting times can be useful to improve sperm quality for artificial insemination purposes in natural conditions.

Sperm motility is one of the most significant parameters in the prediction of male fertility. Until now, both motility analysis using an optical microscope and computer-aided sperm analysis (CASA-Mot) entailed the use of counting chambers with a depth to 20 µm. Chamber depth significantly affects the intrinsic sperm movement, leading to an artificial motility pattern. For the first time, laser microscopy offers the possibility of avoiding this interference with sperm movement. The aims of the present study were to determine the different motility patterns observed in chambers with depths of 10, 20 and 100 µm using a new holographic approach and to compare the results obtained in the 20-µm chamber with those of the laser and optical CASA-Mot systems. The ISAS®3D-Track results showed that values for curvilinear velocity (VCL), straight line velocity, wobble and beat cross frequency were higher for the 100-µm chambers than for the 10- and 20-µm chambers. Only VCL showed a positive correlation between chambers. In addition, Bayesian analysis confirmed that the kinematic parameters observed with the 100-µm chamber were significantly different to those obtained using chambers with depths of 10 and 20 µm. When an optical analyser CASA-Mot system was used, all kinematic parameters, except VCL, were higher with ISAS®3D-Track, but were not relevant after Bayesian analysis. Finally, almost three different three-dimensional motility patterns were recognised. In conclusion, the use of the ISAS®3D-Track allows for the analysis of the natural three-dimensional pattern of sperm movement.

Atlantic salmon (Salmo salar) is an endangered freshwater species that needs help to recover its wild stocks. However, the priority in aquaculture is to obtain successful fertilisation and genetic variability to secure the revival of the species. The aims of the present work were to study sperm subpopulation structure and motility patterns in wild anadromous males and farmed male Atlantic salmon parr. Salmon sperm samples were collected from wild anadromous salmon (WS) and two generations of farmed parr males. Sperm samples were collected from sexually mature males and sperm motility was analysed at different times after activation (5 and 35 s). Differences among the three groups were analysed using statistical techniques based on Cluster analysis the Bayesian method. Atlantic salmon were found to have three sperm subpopulations, and the spermatozoa in ejaculates of mature farmed parr males had a higher velocity and larger size than those of WS males. This could be an adaptation to high sperm competition because salmonid species are naturally adapted to this process. Motility analysis enables us to identify sperm subpopulations, and it may be useful to correlate these sperm subpopulations with fertilisation ability to test whether faster-swimming spermatozoa have a higher probability of success.

For over 30 years, CASA-Mot technology has been used for kinematic analysis of sperm motility in different mammalian species, but insufficient attention has been paid to the technical limitations of commercial computer-aided sperm analysis (CASA) systems. Counting chamber type and frame rate are two of the most important aspects to be taken into account. Counting chambers can be disposable or reusable, with different depths. In human semen analysis, reusable chambers with a depth of 10 µm are the most frequently used, whereas for most farm animal species it is more common to use disposable chambers with a depth of 20 µm . The frame rate was previously limited by the hardware, although changes in the number of images collected could lead to significant variations in some kinematic parameters, mainly in curvilinear velocity (VCL). A frame rate of 60 frames s−1 is widely considered to be the minimum necessary for satisfactory results. However, the frame rate is species specific and must be defined in each experimental condition. In conclusion, we show that the optimal combination of frame rate and counting chamber type and depth should be defined for each species and experimental condition in order to obtain reliable results.

The evaluation of sperm motion is crucial for processing of seminal doses for artificial insemination. Here, the combined effect of the type and capture area of three counting chambers, together with the type of diluent employed, on sperm motility was analysed. Ejaculates from thirteen Holstein bulls were used for sperm kinematic analysis with the ISAS® v1 CASA-Mot system, using two capillary-loaded counting chambers (Leja® and Cell-Vu® ) and one drop displacement chamber (Makler® ). Nine fixed positions were analysed per chamber type, considering central and lateral and three longitudinal fields. Independent of the diluent used, differences were found between the three chambers. Independent of the extender, no differences in x-axis were observed with Cell-Vu® , while using Leja® , some parameters showed lower values in the centre than in lateral areas. In both counting chambers, the lowest values were observed in the distal area. Results obtained with the two diluents were highly different with a very low correlation between them. In conclusion, the capture area inside the chambers leads to significant changes in sperm kinematic parameters and different dilution media introduce considerable differences in the motility patterns. It is necessary to optimise sampling methods and specific set-ups to be used with CASA-Mot technology.

Resumen Los sistemas computadorizados de análisis seminal (CASA, en inglés), se utilizan en reproducción animal con el propósito de valorar de forma rápida y fiable la calidad espermática. Actualmente, en los centros de inseminación artificial se debe disponer de sistemas fiables y objetivos que garanticen una confiabilidad de datos reproductivos. El objetivo fue realizar una revisión acerca de los sistemas de análisis seminal asistidos por computadora, en especies ganaderas. El uso de sistemas CASA sustituye los análisis rutinarios que introducen sesgos y que conlleva a obtener distintos grados de imprecisión. Además, si se consideran las limitaciones intrínsecas de microscopía o espermatozoides con diferentes patrones de movilidad, lo más probable es que se introduzca una variabilidad considerable que repercute en la objetividad de la estimación. En un principio, este tipo de tecnologías eran poco accesibles, pero actualmente se utilizan en la mayoría de laboratorios para la evaluación de muestras espermáticas en distintas especies de interés zootécnico. Las técnicas computadorizadas son capaces de emitir informes con un número elevado de características, minimizar el factor subjetivo de los análisis rutinarios de semen y garantizar una mejor correlación con la capacidad fecundante de los espermatozoides, por medio de las relaciones entre la motilidad espermática y su competencia funcional. El uso de sistemas CASA junto con el análisis estadístico multivariante, han demostrado la existencia de subpoblaciones tanto cinéticas como morfométricas en eyaculados de diferentes especies, desterrando la idea de que los eyaculados son homogéneos, formados por una única población espermática con distribución normal. Abstract Computer-assisted semen analysis (CASA) is used in animal reproduction with the objective of evaluating sperm quality, quickly and reliably. Currently, artificial insemination centers must have reliable and objective systems that ensure the reliability of reproductive data. The aim of this paper was to review computer-assisted semen analysis in livestock species. The use of CASA systems replace routine quality analyzes that introduce biases and leads to different inaccuracy degrees. In addition, if intrinsic limitations of microscopy or sperm with different motility patterns are considered, it is most likely that considerable variability will be introduced which will have an impact on the objectivity of the estimation. At first, this type of technology was inaccessible, but they are currently used routinely in most research laboratories for the evaluation of sperm samples of different species of zootechnical interest.. Computerized techniques are able to issue reports with a high number of characteristics, to minimize the subjective factor of routine semen analysis, and to ensure a better correlation with the fertilizing capacity of spermatozoa by the relationship between sperm motility and functional competence. The use of CASA systems together with multivariate statistical analysis have demonstrated the existence of kinetic and morphometric subpopulations in ejaculates of different species, eliminating the idea that ejaculates are homogeneous, formed by a single sperm population with normal distribution.

Artículo científico This work evaluates sperm head morphometric characteristics in adolescents from 12 to 18 years of age, and the effect of varicocele. Volunteers between 150 and 224 months of age (mean 191, n = 87), who had reached oigarche by 12 years old, were recruited in the area of Barranquilla, Colombia. Morphometric analysis of sperm heads was performed with principal component (PC) and discriminant analysis. Combining seminal fluid and sperm parameters provided five PCs: two related to sperm morphometry, one to sperm motility, and two to seminal fluid components. Discriminant analysis on the morphometric results of varicocele and nonvaricocele groups did not provide a useful classification matrix. Of the semen-related PCs, the most explanatory (40%) was related to sperm motility. Two PCs, including sperm head elongation and size, were sufficient to evaluate sperm morphometric characteristics. Most of the morphometric variables were correlated with age, with an increase in size and decrease in the elongation of the sperm head. For head size, the entire sperm population could be divided into two morphometric subpopulations, SP1 and SP2, which did not change during adolescence. In general, for varicocele individuals, SP1 had larger and more elongated sperm heads than SP2, which had smaller and more elongated heads than in nonvaricocele men. In summary, sperm head morphometry assessed by CASA-Morph and multivariate cluster analysis provides a better comprehension of the ejaculate structure and possibly sperm function. Morphometric analysis provides much more information than data obtained from conventional semen analysis.

Artículo científico DNA fragmentation has been shown to be one of the causes of male infertility, particularly related to repeated abortions, and different methods have been developed to analyze it. In the present study, two commercial kits based on the SCD technique (Halosperm ® and SDFA) were evaluated by the use of the DNA fragmentation module of the ISAS ® v1 CASA system. Seven semen samples from volunteers were analyzed. To compare the results between techniques, the Kruskal-Wallis test was used. Data were used for calculation of Principal Components (two PCs were obtained), and subsequent subpopulations were identified using the Halo, Halo/Core Ratio, and PC data. Results from both kits were significantly different (P < 0.001). In each case, four subpopulations were obtained, independently of the classification method used. The distribution of subpopulations differed depending on the kit used. From the PC data, a discriminant analysis matrix was obtained and a good a posteriori classification was obtained (97.1% for Halosperm and 96.6% for SDFA). The present results are the first approach on morphometric evaluation of DNA fragmentation from the SCD technique. This approach could be used for the future definition of a classification matrix surpassing the current subjective evaluation of this important sperm factor.

Early in his investigations, Leeuwenhoek (1670s) deduced that spermatozoa were alive and an integral part of semen, rather than artifacts or parasites. He eventually observed spermatozoa in the semen of men, dogs, horses, birds, fishes, amphibians, molluscs, and many insects, and concluded that they must be a universal feature of male reproduction. The huge differences in sperm form among species have been discussed in relation to evolutionary changes dictated by the egg and its investments. Spallanzani (1800s) was the first scientist to develop successful methods for artificial insemination, first with amphibians and later with dogs. With these experiments, he showed that physical contact between intact spermatozoa and ova was necessary to achieve the fertilization. Some years later (1820s), Prevost and Dumas performed the defining experiment to identify correctly the function of spermatozoa in reproduction.