An Evaluation of Damage to Bovine Spermatozoa during Processing, Freezing and Thawing II. Effect on Motility, Percentage Live and Ultrastructure of Spermatozoa
Thirty semen samples from five bulls were processed and frozen. Each ejaculate was evaluated for percent progressive motility, percent live spermatozoa and percentage of heads, tails and mid-pieces with intact plasma membrane after collections, after extension and cooling just before freezing and after thawing. The greatest decrease in both motility and percent live spermatozoa occurred before freezing. More spermatozoa heads were damaged at each phase of processing for freezing than mid-pieces and tails and there was also a greater number of damaged spermatozoa before freezing than after freezing and thawing.