The benefits and limitations of the sperm quality analyzer IIB in assessing porcine sperm motility.

The Sperm Quality Analyzer (SQA) IIB, a member of the SQA-II family of machines which uses the scatter of light by sperm as an indicator of sperm motility, was systematically evaluated as a means of analyzing objectively the motility of porcine epididymal sperm. The sperm motility (%) and the Sperm Motility Index (SMI) are calculated by the machine using pre-programmed algorithms designed for human sperm. The machine performed well and was able to detect changes in sperm motility under experimental conditions. However, two major limitations of this machine were identified, (i) the readings obtained were influenced by the concentration of the sperm suspension despite the actual sperm motility remaining constant, and (ii) the machine was unable to differentiate between progressive and non-progressive motility. It should therefore be recognized that (a) the sperm concentration must be kept constant in studies in vitro if differences between treatment groups are to be identified, and (b) the inability to separate progressive motility from that of total motility will restrict the usefulness of this and similar machines to studies monitoring changes in total motility alone.