Ação de diferentes corantes sobre a morfologia espermática de ovinos

Abstract

This study aimed to evaluate the influence of different dyes on the sperm morphology of sheep. To collect semen, three rams were used, approximately 42 months old and with a body weight of 58 kg. Semen collections were carried out weekly and ejaculates were obtained with the aid of an artificial vagina and a conditioned female. In total, ten ejaculates were obtained, which were evaluated for volume (×10⁹ sptz/ml) and then diluted in TRIS. Three aliquots were taken from each ejaculate to prepare smears, which were stained with Bromophenol Blue (AB), Eosin-Nigrosin (EN) and Rapid Panoptic (PO). For each dye, ten semen smears were made and 200 sperm cells/slide were evaluated, totaling 2000 sperm analyzed per dye. After application, the slides were viewed under optical microscopy at 1000× magnification and the sperm images were digitized. Sperm cells were defined as Normal (NOR) and morphological changes as Major Defects (DEMA) and Minor Defects (DEME). The NOR, DEMA and DEME data were submitted to ANOVA using the SAS statistical program. Means were compared using the Tukey test at 5% significance (P< 0.05). In this study, important differences were observed between the dyes used (P<0.05) on sperm morphology. In relation to DEMA, the greatest number of morphological changes was observed under the influence of PO staining (P<0.05). As for morphologically normal spermatozoa, NOR, the highest number is observed in the EN dye (P<0.05), however, this does not differ significantly from AB. In this experiment, no effects of dyes on DEME values were observed (P>0.05). It is concluded that the dyes Bromophenol Blue, Eosin-Nigrosin and Rapid Panotic promote, in different ways, changes in sperm structures. Despite the limitations, Eosin-Nigrosin proved to be the most suitable dye for identifying morphological changes in sheep sperm.