Validation of the Sperm Quality Analyzer (SQA) for dog sperm analysis

Abstract

In the present study, a simple and inexpensive unit (the Sperm Quality Analyzer-SQA), was evaluated for dog sperm analysis. Our objective was to propose a cheap, accurate and convenient device to be used in veterinary practices involved with dog fertility assessment and artificial insemination. The device was tested by analyzing repeatability and accuracy at different sperm concentrations and motility characteritics. The Sperm Motility Index (SMI), a numeric index provided by the SQA, was compared with the results obtained using a computer-aided sperm analyzer (Hamilton Thorn IVOS 10). The correlation between SMI and some sperm parameters as well as predictive values of the SMI were established. The dog sperm data provided by the SQA were consistent and repeatable (coefficient of variability below 10% for all concentrations tested). The SMI was significantly dependant on motile sperm concentration and a positive significant correlation was established for the different motile sperm concentrations from a concentration of 25 x 10 6 up to over 200 x 10 6 cells/mL. Zero motility did not affect SMI because non-motile cells, regardless of their concentration, do not cause any fluctuations in the optical density (OD). Over the tested 200 x 10 6 cells/mL value, a correlation still could be observed but it was not statistically significant, possibly because of a saturation of the system. In dog semen, the correlation is better between SMI values and the number of motile spermatozoa than with the overall motile concentration. Based on this observation, a predictive value was given to the SMI allowing for a sorting of dog ejaculates in 3 sperm categories (SMI <100, 100<SMI<250, SMI>250) each characterized by a range of sperm number and motility. If a positive correlation between the SMI categories and fertility has been demonstrated in humans, such a correlation needs to be established in dogs.