What is the typical gestation length for pigs (sows), and how accurate is the “114 days (3-3-3)” rule?

Most sows farrow around 114 days after a successful service, often quoted as 3 months, 3 weeks, 3 days. Normal variation is about 112–116 days (some earlier/later). Use 114 as the baseline and plan a ±2–3 day window.

What’s a normal farrowing window (early/late), and when should I move the sow to the farrowing area?

A practical window is Due ±2 days (some herds use ±3). Many producers move at ~day 110 of gestation so the sow settles before farrowing, with crate prep and hygiene done a few days ahead.

When should I schedule pregnancy checks and pre-farrowing vaccinations relative to the due date?

Pregnancy check: commonly ~day 25–30 after breeding (ultrasound), and/or watch for a missed return to heat at ~day 21.

Pre-farrowing vaccinations: typically 2–4 weeks before due (follow your vet’s protocol). Many herds also schedule washing/sanitation a few days before farrowing.

How do I pick the right breeding date if I had multiple matings or an AI window over several days?

If you bred over 2–3 days, use the first effective service (or the midpoint if services were spread out and you want a centered estimate). Then apply a ±2–3 day farrowing window. Record all services, your next cycle’s accuracy improves with data.

How do I back-calculate the breeding date if I only know the expected farrowing (due) date?

Subtract your chosen gestation length: Breeding date ≈ Due date – 114 days (adjust if you use a different gestation setting). Keep the same ±2–3 day uncertainty on the back-calculated breeding date.

What weaning age should I plan for (e.g., 21 or 28 days), and how does an early/late farrowing shift the wean date?

Common targets are 21 days (commercial) or 28 days (show/club pigs or management preference). Your wean date = Actual farrow date + chosen wean age, so if farrowing is 2 days early, the wean date is 2 days earlier; if farrowing is late, weaning shifts later by the same amount.