Pigs are pregnant for 114 days, the famous 3 months, 3 weeks, and 3 days, and pig gestation is steady enough that farrowing preparation runs on real dates rather than vague windows. Breed a sow between October 1 and December 1 and she farrows between late January and late March. Because the due date is that reliable, good farrowing preparation is mostly a checklist with a countdown: crate ready by day 107, heat on by day 110, colostrum plan in place before the first piglet hits the floor.
Enter your breeding date in our pig gestation calculator for an exact farrowing date, then work the plan below backward from it.
This page is the prep plan. For why the 3 months, 3 weeks, 3 days rule works and where it comes from, read our 3 months, 3 weeks, 3 days explainer, and for what litter size to expect from a first time gilt, see how many piglets in a first litter.
Breeding to Farrowing at a Glance (114 Day Average)
| Breeding Date | Expected Farrowing (+114 days) | Farrowing Window (112 to 116 days) |
|---|---|---|
| October 1 | January 23 | January 21 to January 25 |
| October 15 | February 6 | February 4 to February 8 |
| November 1 | February 22 | February 20 to February 24 |
| November 15 | March 8 | March 6 to March 10 |
| December 1 | March 24 | March 22 to March 26 |
Calculated at a 114 day average on a non leap year. The window is only plus or minus 2 days, so schedule farrowing checks from the first possible date rather than the average date.
The Farrowing Prep Countdown
Farrowing preparation is a countdown from a date you already know. Here is the full timeline from breeding day to the end of farrowing:
Day 0: breeding
Record the date, plan the crate
Pig gestation is so consistent that the farrowing date is almost fixed the moment breeding happens. Write the date down, add 114 days, and book that week. The 112 to 116 day window means your farrowing room schedule can be trusted in a way cattle and goat schedules cannot.
Days 21 to 28
Confirm the pregnancy
Have the pregnancy confirmed by ultrasound or an A mode detector in this window. Non pregnant sows caught now can be rebred on the next cycle instead of eating a full gestation's feed for nothing.
Days 30 to 100
Feed to condition, treat on schedule
Adjust the gestation ration to hold body condition, and run any deworming or vaccination your vet schedules during this quiet middle stretch. Gilts, pregnant for the first time, need extra nutrition for their own continued growth.
About day 107
Wash the sow, move her in
Five to 7 days before farrowing, wash the sow to remove manure and worm eggs, then move her into the cleaned, disinfected crate. The wash matters: much of the scours pressure on newborn piglets rides in on a dirty sow.
About day 110
Heat on, watch the udder
Turn the heat mat on or hang the heat lamp over the creep area so the zone is warm before the first piglet arrives. Start checking the sow's udder and vulva daily; milk letdown and restlessness usually appear in the final 24 hours before farrowing.
Farrowing day and after
Attend, dry, and get piglets nursing
Farrowing typically runs 2 to 5 hours with a piglet arriving every 15 to 20 minutes. Dry each piglet, make sure it nurses colostrum within hours, and call the vet if active farrowing stalls past an hour between piglets.
Farrowing Crate Setup
The crate exists to stop sows from lying on piglets, and a poorly set up crate protects no one. Before the sow goes in:
- Power wash and disinfect crate, floor, and feeder, then let it dry fully before bedding
- Check bars and floors for gaps and sharp edges that catch piglet legs
- Keep the heated creep on one side; never heat the whole crate
- Check water flow, since a lactating sow drinks several gallons a day
- Bed lightly so piglets cannot burrow under loose material and get trapped
- Test lighting and make sure you can reach any piglet without crawling through the sow's space
Heat Mats and Piglet Temperature
Piglets are born with almost no body fat, and their body temperature drops fast in a cool room. The fix is a warm creep zone at roughly 95 degrees Fahrenheit (35 degrees Celsius) for the first days, while the sow stays comfortable at room temperature around 68 to 72 degrees Fahrenheit. Turn the heat mat on a day before farrowing so the zone is already warm, and position the lamp so piglets can move between the udder and the warm zone freely. A chilled piglet rarely goes back to the udder on its own, which is why warmth and colostrum are the same job.
Colostrum Planning for Big Litters
Sows farrow litters of 6 to 12 piglets over several hours, which means the first born have been waiting on colostrum while the last are being delivered. Piglets absorb antibodies best in the first 6 hours, so plan access rather than hoping: move early born piglets back to the udder between deliveries, split suckle very large litters so everyone gets a turn, mix colostrum replacer for the smallest piglets, and cross foster within the first day when the litter outruns the sow's milk supply.
Keep towels, a warming box, replacer, a bottle, iodine for navels, and iron for the day 3 injection by the crate. Track each piglet's nursing on a card, because the runt that quietly misses colostrum in hour five is a preventable loss.
As dates approach, the pig farrowing calculator keeps the countdown visible, and the printables page has record sheets for the farrowing room wall.
Sources & References
- Merck Veterinary Manual: swine reproduction and farrowing management
- Iowa State University Extension: Iowa Pork Industry Center farrowing resources
- Purdue Extension: swine husbandry references
- University of Minnesota Extension: swine health and management