Sheep Gestation Period: How Long Is a Sheep Pregnant?

How long is a sheep pregnant?

A sheep carries her lamb for an average of 147 days, or about 4 months and 3 weeks. Counting from the breeding date, lambing is normal anywhere from day 144 to day 152.

Key checkpoints across the 147-day sheep gestation, measured in days from breeding:

Estimate your sheep's lambing date

Enter the breeding date for an estimated lambing date at 147 days.

Open the full Sheep gestation calculator

Sheep gestation stages, month by month

Signs a sheep is pregnant

• No raddle mark from the ram and no return to heat about 17 days after service
• Belly deepens and widens on both sides from roughly day 100, more asymmetrically with twins
• Ultrasound scanning from day 45 confirms pregnancy and counts lambs accurately
• Udder develops from about four weeks out and fills firmly in the final week

Signs of approaching lambing

• The ewe separates from the flock, paws at bedding and lies down and gets up repeatedly
• A clear string of mucus from the vulva means lambing is usually within hours
• Contact your vet if labour stalls, if the animal strains without progress, or if there is abnormal discharge before lambing begins.

What affects sheep gestation length

• Ewes are short-day breeders, so most flocks in temperate climates conceive in autumn and lamb in spring without any hormonal help.
• Prolific breeds carry lambs for a shorter time: Finnsheep and Romanov ewes commonly lamb at 143 to 144 days, while Merino and Rambouillet ewes run to 148 or 149.
• Each extra lamb in the uterus shortens gestation by roughly one day, so a ewe carrying triplets will usually lamb before a single-bearing ewe served on the same day.
• Around 70 percent of lamb growth happens in the last six weeks, which is also when pregnancy toxaemia and hypocalcaemia appear in underfed or over-fat ewes.
• Ewes lambing as ewe lambs in their first year tend to carry two to three days longer than mature ewes and need feeding as growing animals as well as pregnant ones.

Sheep gestation chart

Every fifth breeding date across the year with the matching lambing date, calculated at 147 days. Find the row closest to the date the sheep was served; because normal gestation spans 144 to 152 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.

Sheep gestation length by breed

Sources for sheep gestation figures

Figures on this page are drawn from breed society gestation records, sheep flock health guidance and published ovine 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.

• 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