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Routine evaluation of the sperm of livestock animals involves detection of morphological abnormalities. However, most sperm defects that reduce fertilizing capacity are a result of anomalies in spermatogenesis. The aim of the study was to evaluate the effect of a boar's age on the stability of the genetic material of its sperm. The age of the boar was found to have a significant effect on sperm DNA stability and chromatin structure. The highest percentage of spermatozoa with DNA fragmentation was found in the oldest group of boars (0,61%), while the highest proportion of spermatozoa with abnormal histone retention (8,01%) and protamination (9,78%) was found in the youngest group of boars. Aniline blue (AB), chromomycin A3 (CMA3) and acridine orange (AO) staining should be routinely used in individuals used for artificial insemination especially young animals at the start of their exploitation for breeding, as well as older individuals with an age-related decrease in the stability of genetic material. Earlier diagnosis based on additional tests would allow for stricter selection and elimination of males with fertility disorders from breeding, to be replaced by breeders of full value. It was also demonstrated that all three staining methods mentioned above can be used in classical morphological analysis, because they clearly distinguish the sperm head from the background of the slide. Chromomycin staining clearly reveals the midpiece and thus can be used as a specific staining method for its evaluation. Staining with aniline blue is a fast and simple test whose result can be analysed under a light microscope. This staining technique can be recommended for use at insemination stations. • The age of the boar influences the structure of spermatozoon chromatin. • The epigenetic sperm defects are identified in normal spermatozoa. • The disturbed chromatin structure is not identified during routine semen analysis. [ABSTRACT FROM AUTHOR]

Nucleoli are the product of the activity of nucleolar organizer regions (NOR) in certain chromosomes. Their main functions are the formation of ribosomal subunits from ribosomal protein molecules and the transcription of genes encoding rRNA. Nucleoli are present in the nuclei of nearly all eukaryotic cells because they contain housekeeping genes. The size and number of nucleoli gradually decrease during spermatogenesis. Some of the material originating in the nucleolus probably migrates to the cytoplasm and takes part in the formation of chromatoid bodies (CB). Nucleolus fragmentation and CB assembly take place at the same stage of spermatogenesis. CB are involved in the formation of the acrosome, the migration of mitochondria to the midpiece, and the formation of the sperm tail fibrous sheath. The aim of the study was to characterize the nucleoli in the early prophase of spermatogenesis in the wild boar and the roe deer. The roe deer cells have larger nucleoli and a larger cell nucleus than the wild boar cells. The area of the nucleolus as a percentage of the total area of the nucleus was larger as well. The coefficients of variation for all parameters were higher in the roe deer. In the wild boar cells the nucleoli were mainly regularly shaped. The size of the nucleolus and the nucleus of the spermatocyte is a species-specific trait associated with karyotype and the number of nucleolar organizer regions in a given species. [ABSTRACT FROM AUTHOR]

Sperm morphometry has some value as an indicator of reproductive capacity in males. In laboratory practice a variety of slide-staining methods are used during morphological evaluation of semen to predict male fertility. The aim of this study was to determine the effect of staining of semen using four different techniques on the morphometry of the bull sperm cell. The material for the study consisted of semen collected from test bulls of the Black-and-White variety of Holstein-Friesians. The results obtained in the study indicate differences in the dimensions of bull sperm heads when different slide staining techniques were used. The most similar results for sperm head dimensions were obtained in the case of SpermBlue ® and eosin + gentian violet complex, although statistically significant differences were found between all the staining techniques. Extreme values were noted for the other staining techniques – lowest for the Papanicolaou and highest for silver nitrate, which may indicate more interference in the cell by the reagents used in the staining process. However, silver nitrate staining was best at identifying the structures of the sperm cell. Hence it is difficult to determine which of the staining methods most faithfully reveals the dimensions and shape of the bull sperm. [ABSTRACT FROM AUTHOR]

A problem in evaluating the morphology and morphometry of sperm is the lack of standardization of staining techniques. The method of staining and evaluating specimens can significantly affect the results of morphometric measurements. The aim of the study was to determine the effect of two techniques for staining stallion sperm on the morphology and morphometric dimensions of sperm cells and the formation of artefacts. The subject of the study was the sperm of Polish Half Bred stallions, isolated post mortem from the tail of the epididymis. Morphometric measurements were made of the following: length, width, perimeter and surface area of the sperm head, surface area of the acrosome, midpiece length, tail length and total sperm length. Sperm evaluation was expanded to include acrosome coverage, i.e. the surface area of the acrosome as a percentage of the total area of the sperm head, and a characterization of the tail, particularly the midpiece. Tygerberg strict criteria were used to evaluate sperm morphology. The data show that the staining method and the chemical reagents applied have a substantial effect on the dimensions and shape of the stallion sperm. The literature on the subject draws attention to the fact that a staining technique should be established or developed which would enable precise and unambiguous analysis of the morphology and morphometry of human and animal spermatozoa. Moreover, a standard should be developed for preparing specimens for morphological analysis. This would enable comparison of results between laboratories, thus enhancing the value of morphological analyses of sperm in predicting and evaluating fertility. [ABSTRACT FROM AUTHOR]