Due to the high temperature The addition of citric acid to it. The pH-value decreases As a result, the conductivity increases. The cells can not withstand harsh conditions and at high temperatures. And much more acidity. It has reduced the number significantly.
Because of the high temperature. When the citric acid in the pH reduced, resulting in a higher electrical conductivity The cell can't endure conditions at high temperature and pH very, therefore has reduced sperm clearly.