Abstract
Potassium (16 to 64 mM) adversely affected ram spermatozoa during cooling from 30 to 5[degree]C, while magnesium was beneficial. The effect of potassium was independent of the rate of chilling or the dilution of semen between 1 in 10 and 1 in 20, but it was decreased by increasing the sodium content of the diluent and was increased by the presence of phosphate. The addition of potassium after chilling did not affect subsequent motility. High potassium levels during chilling were detrimental to washed ram spermatozoa. Low levels, on the other hand, helped to maintain the motility of washed cells during the period of storage. The addition of seminal plasma did not modify the effect of potassium on washed cells.