Fluorometry of poultry semen: influence of dilution and storage on chicken spermatozoal viability and fertility.

Two experiments were conducted to measure the effects of semen dilution and storage time (0, 1, 2, 3, 4, 24, and 48 h) at 22 C on spermatozoal viability (i.e., membrane permeability to ethidium bromide) and to determine the relationship between concentration of viable spermatozoa inseminated (25, 50, 100, and 200 x 10(6] and fertility. In Experiment 1, percentages of dead spermatozoa remained relatively constant during the 4-h postcollection period but increased significantly (P less than .05) at 24 and 48 h. Sperm viability after 48 h was significantly higher in diluted semen than in undiluted semen. Percent (PF) and duration of fertility (DF) from undiluted semen significantly declined during the 4-h postcollection period compared with fertility of diluted semen. In Experiment 2, both PF and DF improved as the concentration of viable spermatozoa increased. Fertility was not significantly improved by inseminating more than 100 X 10(6) viable spermatozoa. The fertilizing capacity of chicken spermatozoa from undilated semen was affected during storage before membrane permeability to ethidium bromide was altered.