Viability assays for frozen semen

Abstract

The ultimate assay determining viability of frozen semen is the birth of healthy offspring but it requires time and money. Researchers have tried to develop an objective, reliable assay for predicting the fertility of frozen semen immediately after laboratory treatment, avoiding loss of time and expense of multiple breedings in field fertility trials. Bishop (1955) measured 11 characteristics of semen including morphology, metabolism, and motiIity assays and correlated the resuIts with fertility. He reported significant relationships but concluded none were meaningful for determining fertility. Cupps et d. (1953) studied the relationship of sperm concentration, motility, fructolysis index, percentage dead, and percentage abnormal sperm with fertility. They reported correlation values of I = -0.51 for percentage dead and T = -0.83 for percentage abnormal sperm. Stewart et al. (1972) studied seven semen assay techniques including morphoIogy, motility, and motility as measured by the electronic instrument developed by Glover (1968). One significant relationship (I’ < 0.05) between fertility and measured motility was reported, T = 0.41. Hirao (1975) correlated five chemical parameters of semen and motility with fkrtility and reported motility alone (T = 0.654) as significant with simple correla-