How it works
Pigs are remarkably consistent. The average gestation across breeds and parities lands almost exactly on 114 days from breeding to farrowing.
Add 114 days to a breeding date and you have a due date. Subtract 114 from a target due date and you know when to breed. Build the rest of the husbandry calendar around those two anchors.
due_date = breeding_date + 114 days
Frequently asked
How accurate is the due date?
Within two days for most healthy sows. Gilts (first-time mothers) sometimes farrow a day or two earlier. Older sows and certain heritage breeds may run a day or two later. Big litters tend to come slightly early.
When should I do a pregnancy check?
Around day 28–30 by ultrasound. Blood tests can confirm pregnancy as early as day 21. Visual signs (no return to heat by day 21, body changes) are unreliable until later.
What signs mean farrowing is imminent?
Milk in the teats (12–24 hours out), visible nest-building behavior (6–12 hours), restlessness and breathing changes (1–4 hours), discharge from the vulva (under 1 hour). When milk drips freely, piglets are typically within an hour or two.