Assuming a normal farrowing process with no difficulties, the uterus should gradually return to its nonpregnant size within 10 or 12 days.
Assuming a normal farrowing process with no difficulties, the uterus should gradually return to its nonpregnant size within 10 or 12 days.
Lactation (nursing a litter) sends neuroendocrine signals to sows’ hypothalamus (in the brain) which inhibits her from coming back into estrus by suppressing GnRH release.
When the litter is weaned this signal is no longer present and her endocrine system(hormones) can “reset” itself.
- GnRH (Gonadotropin Releasing Hormone) is released from the hypothalamus and travels to the pituitary gland. ( remember this gland is located at the base of the brain).
- GnRH stimulates the pituitary gland to secrete LH and FSH which travel in the blood to the ovaries and in turn stimulate follicular growth and development.
- Normally within 4 to 8 days after weaning this process is complete and the follicles begin to develop on the ovaries and they secrete enough estradiol to return the sow to estrus.