Comparative study of testicular cytology in the ram, boar and alpaca

The aim of this study was to investigate effectiveness of testicular aspiration cytology in the ram, boar and alpaca. Testicular Fine Needle Aspiration Cytology was performed in rams (N=18), boars (N=8) and alpacas (N=5) using a 21G butterfly needle and 20 ml syringe. Slides were stained using a modified May-Grünwald-Giemsa staining. Cells were evaluated at 1000x magnification assessing the composition of testicular cells, relative percentage of spermatogenic cells and specific indexes of sperm production. Cells morphology did not differ between species, with the exception that in alpaca they look slightly greater. Quantitative analysis shows some differences between species. Intra-species statistical evaluation included effect of different nutrition, treatment of spermatogenesis suppression and comparison of aspiration versus impression cytology. Aspiration cytology was successful in identifying the effect of different treatments and was more precise than impression in characterizing spermatogenesis