The effect of twenty-four hour in vitro storage on sperm hydrolysis through the perivitelline layer of ovipositioned turkey eggs.

Counting the holes in the perivitelline layer surrounding the germinal disc of freshly laid eggs has been used as a means of assessing sperm attachment, their ability to undergo an acrosome reaction, and penetration of the ovum, all necessary steps in the process of fertilization. The objective of this study was to compare the number of holes in the perivitelline layer of eggs after insemination with fresh turkey semen or with semen stored in vitro for 24 h. Hens (n = 40) were inseminated weekly with either 100 x 10(6) or 10 x 10(6) liable sperm within 90 min of collection or 24 h after in vitro storage at 5 C. A minimum of 20 eggs per treatment group were evaluated for the number of holes in the perivitelline layer. Fertility and hatchability were determined for all other eggs. The number of holes in eggs from hens inseminated with 100 x 10(6) sperm was higher (P < 0.05) for fresh (119 +/- 23 holes per egg) vs stored (75 +/- 5 holes per egg) semen treatments over the 10-wk study period. Holes observed in the perivitelline layer of eggs from hens inseminated with 100 x 10(6) sperm were more numerous than those inseminated with 10 x 10(6) sperm (P < 0.05). The number of holes observed for fresh and stored 10 x 10(6) groups were 6 +/- 3 and 7 +/- 4 holes per egg, respectively. Fertility was higher for the eggs from hens inseminated with 100 x 10(6) sperm than for those from hens inseminated with 10 x 10(6) sperm (P < 0.05). Hatchability of fertile eggs was higher for the 100 x 10(6) dose eggs than for eggs that received the low dose but did not differ between fresh and stored treatments. This report shows that the number of sperm that hydrolyze through the perivitelline layer is reduced after in vitro storage of semen.