Types of ovulation

TYPES OF OVULATION

Spontaneous ovulators

  • In many species ovulation occurs spontaneously after normal follicle growth during estrus cycle. Eg: cow, goat, mare, sow, primate
  • i.e a secretory pattern of estrogen associated with a developing follicle is able to cause a rise in LH release that causes ovulation.

Induced ovulators

  • Eg: Cat, rabbit, ferret, mink and members of camilidae family.
  • Induced ovulators are animals that do not ovulate spontaneously even in association with normal follicle development.
  • Vaginal stimulation during copulation initiates neuroendocrine reflex that results in ovulation. Estrogen priming of the hypothalamus and anterior pituitary is essential prerequisite for copulation to induce GnRH and LH release leading to ovulation.

Ewe
24 hrs
after onset of estrus
Doe
24 – 36 hrs
after onset of estrus
Pig
38 – 42 hrs
after onset of estrus
1 -2 days
Before the end of estrum
Cat
24 – 36 hrs
Post copulation
Rabbit
10.5 hrs
Post copulation
Cow
12 – 14 hrs
after end of estrus
Dog
Near the beginning of estrus
Fertilization takes place after 4th day

Last modified: Wednesday, 20 June 2012, 5:44 AM