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.
Semen was collected from Polish Halfbred stallions. Twenty individuals from 3 to 4 years of age were selected for the study. At least one ejaculate from each stallion was collected and assessed. Sperm morphology was evaluated using Papanicolaou stain, SpermBlue ® , and a complex of eosin and gentian stain, whereas unstained slides were used as control samples. Morphometric measurements were performed on 100 randomly selected sperm heads in each ejaculate. The length, width, perimeter, and surface area of the sperm head were measured. The frequency of nuclear vacuoles was determined as well. Tygerberg's strict criteria, which most precisely characterise the sperm head, were used in the morphological evaluation of the sperm. The results obtained indicate that in the case of staining with SpermBlue ® and with eosin+gentian complex, the morphometry of the sperm head seems to be most similar to that observed in unstained smears. It also seems that neither shrinking nor swelling is uniform in the various staining techniques (Papanicolaou stain). Moreover, it appears that in comparison with unstained sperm, all methods caused the width of the head to increase as a result of swelling.
The study was conducted on spermatozoa of selected farm and free-living animal species, isolated post mortem from the tail of the epididymis, and stained with silver nitrate -AgNO3. The material was collected from pigs, goats, wild boar, and European roe deer. Twenty morphologically normal spermatozoa randomly selected from each animal and well visible under the microscope, were analysed. The following measurements were considered: head length, width, perimeter and area, acrosome area, mid-piece length, tail length, and overall sperm length. AgNO3 staining differentiated the acrosomal (light hue) and distal (dark hue) part of the sperm head, and a light-hued mid-piece was visible within the sperm tail. Silver nitrate staining revealed species and variety-related differences, particularly in reference to the sperm head. Clear-cut differentiation within the head and tail area made it possible to perform detailed morphometric measurements of the spermatozoa.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.