Effect of various capacitation systems on bovine sperm motion characteristics, acrosome integrity, and induction of hyperactivation.

Sperm from the same ejaculate were capacitated in TEST-yolk, calcium-free Tyrode's, modified Tyrode's containing follicular fluid or heparin, and analyzed at 0, 4, 8, and 12 h for motility characteristics and acrosomal integrity. Percentage of motility, progressive motility, progressive velocity, path velocity, curvilinear velocity, linearity, and amplitude of lateral head displacement differed with media and decreased with time. Calcium-free Tyrode's ranked first in maintaining most motility parameters. However, TEST-yolk sperm ranked first for lateral head displacement but last for linearity at each time. Acrosome-reacted sperm increased over time but were not different between TEST-yolk, calcium-free Tyrode's, and heparin at 4 h. The TEST-yolk sperm at 4 h had about twice the hyperactivation (62.3%) of the other sperm capacitation media. Capacitation of bovine sperm was not associated with a specific change in any measured motility parameter. Differences among the efficacies of capacitation systems were unrelated to parameters of sperm motion, hyperactivation, or acrosomal integrity.