Pig Gestation Period: How Long Is a Pig Pregnant?

How long is a pig pregnant?

A pig carries her piglet for an average of 114 days, or about 3 months and 3 weeks. Counting from the breeding date, farrowing is normal anywhere from day 112 to day 116.

Key checkpoints across the 114-day pig gestation, measured in days from breeding:

Estimate your pig's farrowing date

Enter the breeding date for an estimated farrowing date at 114 days.

Open the full Pig gestation calculator

Pig gestation stages, month by month

Signs a pig is pregnant

• No return to heat 21 days after service and no standing for the boar
• Ultrasound confirmation from about day 28
• Belly drops and widens from roughly day 75, with visible teat line development
• Teats become prominent and the udder firms up in the final two weeks

Signs of approaching farrowing

• Milk can be expressed from the teats within about a day of farrowing
• Intense nest building, restlessness and chewing at straw 12 to 24 hours before farrowing
• Contact your vet if labour stalls, if the animal strains without progress, or if there is abnormal discharge before farrowing begins.

What affects pig gestation length

• Pig gestation is famously easy to remember as three months, three weeks and three days — 115 days — and it is one of the tightest gestations in farm livestock.
• Larger litters farrow slightly earlier: a sow carrying 16 piglets often farrows a day before a gilt carrying eight served on the same day.
• Gilts (first-time mothers) tend to farrow around a day earlier than mature sows and produce smaller, lighter litters.
• Roughly two thirds of piglet weight is laid down in the last three weeks, so the feed increase around day 75 matters far more than anything fed earlier.
• Sows are the classic nest builders of farm livestock: given straw, a sow will carry and arrange bedding intensely in the 12 to 24 hours before farrowing.

Pig gestation chart

Every fifth breeding date across the year with the matching farrowing date, calculated at 114 days. Find the row closest to the date the pig was served; because normal gestation spans 112 to 116 days, plan for a window of a few days either side. Filter by month, or print the chart for the barn wall or breeding record: navigation, buttons and adverts are hidden on paper.

Pig gestation length by breed

Sources for pig gestation figures

Figures on this page are drawn from commercial swine breeding records, pig herd health guidance and published porcine reproduction studies, and checked against the references below. Averages describe healthy animals under normal management; individual animals vary, and nothing here replaces advice from your vet.

• National Pork Board, swine care handbooks
• Merck Veterinary Manual — reproduction and pregnancy chapters by species
• Penn State Extension — livestock reproduction and breeding management fact sheets
• Oklahoma State University, Breeds of Livestock