Dilution of fowl semen with phosphate or saline diluents depressed respiration, while dilution with seminal plasma did not affect respiration. Dilution with Tyrode solution resembled dilution with seminal plasma with respect to respiration. The effect of Tyrode solution seemed to be mainly due to its NaHCO3 content.
The effect of Ca, Mg and K ions depended on the anions in the diluents. Phosphate depressed respiration and glycolysis when it replaced saline in the Tyrode diluent.
Dilution did not consistently increase respiration and in most cases depressed respiration.
Fowl sperm preferentially utilized glucose when glucose and fructose were initially present in equal concentration in the diluent. The sperm metabolize glucose at a faster rate than fructose. No evidence was found for the formation of glucose from fructose under our experimental conditions.
Initial respiration and glycolysis of fowl semen was depressed by the addition of glycine to the Tyrode diluent. However, the glycine addition resulted in a less sharp decrease in the hourly respiration rate.