Gamete physiology and timing of ovulation and fertilization in dogs
Tsutsui, T.
Journal of Reproduction and Fertility. Supplement 39: 269-275
1989
ISSN/ISBN: 0449-3087 PMID: 2621728 Document Number: 328038
Ovulation in most bitches studied occurred between 48 and 72 h from the onset of oestrus. The eggs were ovulated as primary oocytes, and were not capable of being fertilized until about 60 h after ovulation, at which time they underwent the 1st meiotic division to become secondary oocytes. By this time, the ova had descended through two-thirds of the oviduct. Ova were fertilizable from the time of undergoing the 1st meiotic division at 60 h after ovulation until about 108 h after ovulation. The period during which the spermatozoa remained capable of fertilization in the female reproductive tract was though to be about 5 days. The mating period during which conception was possible was thus about 7 days from the onset of oestrus.