Fertilizing capacity and ultrastructure of fowl and turkey spermatozoa before and after freezing

Abstract

The fertilizing capacity, motility and ultrastructure of fowl and turkey spermatozoa were examined at various stages of the freezing process. For both species, fertility and motility were depressed after equilibration with dimethylsulfoxide at 5.degree. C. After freezing, motility was maintained at 55% for fowl spermatozoa and 40% for turkey spermatozoa. Fertility was 55% for the fowl and 0% for the turkey. Qualitatively, the damage to the spermatozoa of both species was nearly identical, as revealed by scanning and transmission electron microscopy. The plasmalemma was the primary site of damage. Bent spermatozoa, coiled tails and swollen mitochondria were also present. Damage to the acrosome was observed only in spermatozoa which were frozen to -180.degree. or -196.degree. C. These changes were attributed to adverse osmotic conditions. Binding of cationic ferritin to the plasmalemma of spermatozoa from both species remained unaltered.