IntroductionThe effect of two smear staining methods on the dimensions and shape of sperm cells in the semen of domestic pigs was evaluated.Material and MethodsThe studies were carried out on 30 ejaculates collected from 15 boars, which included five Duroc boars, five Pietrain boars, and five hybrid Duroc × Pietrain boars. Each ejaculate was next sampled to make two microscopic slides, of which one was stained with eosin-nigrosin and the other with eosin-gentian dye. In total, 600 measurements of sperm cells were made. Each sperm was measured for the following morphometric parameters: head length, head width, head area, head perimeter, tail length, and the total sperm length.ResultsSperms measured on slides stained with eosin-nigrosin showed lower dimensions as compared with those stained with the eosin-gentian dye method. Sperm stained with eosin-nigrosin had shorter and narrower heads than sperm stained with eosin-gentian dye. The method of staining, therefore, affected not only the dimensions of the sperm, but also the proportions of the dimensions defining the shape of the sperm.ConclusionsThe size and shape parameters in porcine sperm may take on different values depending on the method of semen staining. Sperm cells stained with eosin-nigrosin are smaller than the sperm stained with eosin-gentian dye. The sensitivity of the sperm to the type of dye used for the fixation may be associated with genetic factors.

Introduction: The aim of this study was to propose the optimal methodology for stallion semen morphology analysis while taking into consideration the staining method, the microscopic techniques, and the workload generated by a number of samples. Material and Methods:Ejaculates from eight pure-bred Arabian horses were tested microscopically for the incidence of morphological defects in the spermatozoa. Two different staining methods (eosin-nigrosin and eosin-gentian dye), two different techniques of microscopic analysis (1000× and 400× magnifications), and two sample sizes (200 and 500 spermatozoa) were used. Results: Well-formed spermatozoa and those with major and minor defects according to Blom's classification were identified. The applied staining methods gave similar results and could be used in stallion sperm morphology analysis. However, the eosin-nigrosin method was more recommendable, because it allowed to limit the number of visible artefacts without hindering the identification of protoplasm drops and enables the differentiation of living and dead spermatozoa. Conclusion: The applied microscopic techniques proved to be equally efficacious. Therefore, it is practically possible to opt for the simpler and faster 400x technique of analysing sperm morphology to examine stallion semen. We also found that the number of spermatozoa clearly affects the results of sperm morphology evaluation. Reducing the number of spermatozoa from 500 to 200 causes a decrease in the percentage of spermatozoa identified as normal and an increase in the percentage of spermatozoa determined as morphologically defective.

The aim of this study was to compare ejaculates of Duroc and Pietrain boars in terms of sperm morphology characteristics. Analysis was performed on 116 ejaculates collected from 6 Duroc boars and 9 Pietrain boars. The boars selected for examination were young and at the beginning of their reproductive utilization. Ejaculates were collected at monthly intervals over the period of 10 months. Microscopic slides were prepared immediately after collection of ejaculates. The slides were examined to assess the frequency of morphological abnormalities. Moreover, morphometric measurements were taken from 15 randomly selected morphologically normal spermatozoa. Also, conventional evaluation of ejaculates was made following methods used at Polish sow insemination centres. Differences were found in the dimensions and shape between Duroc and Pietrain spermatozoa. Pietrain spermatozoa were characterised by significantly smaller head perimeter compared with Duroc (P ≤ 0.01). Moreover, Pietrain spermatozoa tails were by 0.8 μm longer (P ≤ 0.01), and their total sperm length was greater by 0.5 μm compared to Duroc (P ≤ 0.05) sperm. The volume of Duroc ejaculates was lower but their sperm concentration was greater. The results of the present study contribute to scientific progress as they demonstrate differences in sperm size between boars of different breeds, which may be reflected in different reproductive performances of the boars. Pigs, purebreed, ejaculate, morphometryThe breeding value of boar depends on the quantity and quality of semen produced. Ejaculate variation is the product of an influence of many factors including race (Smital et al. 2004), season of the year (Wysokińska et al. 2009b), boar age (Deka et al. 2002) as well as utilization intensity (Frangez et al. 2005). Depending on the breed, ejaculates have different volumes, semen concentrations and percentages of progressively motile spermatozoa. There are also differences in fertilization efficiency, fertility and overall semen evaluation.The aim of this study was to comparatively analyse Duroc and Pietrain boars used for artificial insemination in terms of sperm morphology. Materials and MethodsThe study was conducted on 8-9-month-old boars at the initial stage of their reproductive utilization. A total of 116 ejaculates were examined. They were collected from 6 Duroc and 9 Pietrain boars utilized at two sow artificial insemination stations owned by the Mazovian Centre of Animal Breeding and Reproduction in Lowicz, Poland. Ejaculates were collected at monthly intervals with the "gloved-hand" method during the period of 10 months. Immediately after collection one microscopic slide for examinations was prepared from each ejaculate. A thin sperm smear was applied to a degreased microscope slide and fixed in a 96% ethanol solution for 5 min. Then, the preparation was rinsed in distilled water and stained with a 10% eosin aqueous solution for 20-60 s. The stained preparations were rinsed in distilled water and stained with gentian-violet dye for 3-5 min. Aft...

The experimental material consisted of 75 ejaculates collected form 8 Duroc boars. The ejaculates were divided into three groups according to sperm concentration in an ejaculate. An ejaculate was obtained from each boar monthly and it was used to make microscopic preparations to examine spermatozoa morphology. In each preparation morphometric measurements were taken of fifteen randomly selected spermatozoa characterized by normal morphology. The following measurements of spermatozoa were taken: length and width of the spermatozoa head, head area, length of the flagellum, perimeter of the spermatozoon head and total spermatozoon length. The results were used to calculate indicators of spermatozoa morphology. Moreover, assessments were made of frequency of morphological defects to isolate spermatozoa with primary and secondary abnormalities following the Blom classification system. It was found that the concentration of spermatozoa in the ejaculate influenced the morphometric characteristics of spermatozoa. Ejaculates with low sperm concentrations are characterized by larger spermatozoa as compared to ejaculates with high sperm concentrations. However, sperm concentration in the ejaculate does not much influence the shape of spermatozoa.

The study was performed on 4 609 ejaculates obtained from 32 boars, including 14 purebred and 18 two-breed crosses. The ejaculates were collected manually every 4-5 days. The study involved ejaculates collected from each boar from the first day of its insemination use until the day of semen depletion. Each ejaculate was assessed for the following physical parameters: ejaculate volume, sperm concentration, percentage of spermatozoa with correct motility, total sperm count per ejaculate and number of insemination doses obtained from one ejaculate. The effect of heterosis was calculated on the physical parameters of the boar crosses ejaculates in relation to the mean value of a given parameter for the parent breeds. Positive and well pronounced heterosis effects were identified in the majority of the physical ejaculate parameters of the cross boars for all the cross-breeding variants. A negative effect of heterosis was only identified in the ejaculate sperm concentration of the Hampshire × Pietrain crosses. The highest ejaculatory efficiency was identified in the hybrids produced on the basis of the Hampshire breed. These breeders were also found to feature significant heterosis effects on ejaculate volume, total ejaculate sperm count and number of insemination doses prepared from one ejaculate.