Sheep Gestation Period: How Long Is a Sheep Pregnant?

A sheep is pregnant for about 147 days, roughly 4 months and 3 weeks. Normal lambing happens between 144 and 152 days, and a typical litter is 1-2 lambs.

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:

Sheep gestation timeline from day 0 to day 147: day 17 Ewe returns to heat if not in lamb — watch the ram's marks; day 45 Scanning window opens: ultrasound counts lambs from day 45 to 90; day 100 Split the flock by lamb count and lift the ration for twins and triplets; day 125 Clostridial and pasteurella booster so colostrum carries antibodies; day 135 Crutch or dag the ewes and move them to the lambing paddock or shed; day 147 Expected lambing.

Sheep gestation stages, month by month

Days 1–30: fertilisation and implantation

The embryos travel to the uterus and attach from about day 15. Do not shear, dip, drench with anything unapproved or move ewes long distances in this window; embryo loss here shows up later as an unexpectedly empty ewe. Keep the ration steady rather than suddenly generous.

Days 31–90: placental development and scanning

The placenta rather than the lamb is doing most of the growing, so nutrient demand is close to maintenance and ewes can hold their own on grass or moderate hay. Scan between day 45 and 90 to count lambs — this single measurement drives every feeding decision for the rest of the pregnancy.

Days 91–125: feeding to lamb number

Foetal growth accelerates and rumen capacity starts to fall as the uterus takes up space. Feed twin- and triplet-bearing ewes separately, aim for body condition score 3 to 3.5 at lambing, and give clostridial boosters around day 125 so colostrum is loaded with antibodies.

Days 126–147: pre-lambing

Energy demand peaks: a ewe with twins needs roughly twice the maintenance energy of a dry ewe. Watch for twin lamb disease in ewes that go off feed. The udder fills, the vulva slackens and softens, and the ewe drifts away from the flock and paws bedding hours before lambing.

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.

Estimate your sheep's lambing date

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

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Breeding date

Estimated lambing date

Saturday, 6 February 2027

Earliest

3 Feb 2027

Latest

11 Feb 2027

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Sheep pregnancy FAQs

How long is a sheep pregnant?

About 147 days, which is roughly five months, with a normal range of 142 to 152 days. Prolific breeds such as Finnsheep lamb closer to 143 days and fine-wool breeds such as Merino closer to 148.

Does breed change a ewe's gestation length?

Yes, by up to a week across the extremes. The table above lists common breeds: Finnsheep and Romanov at 143 to 144 days through to Karakul at about 150. Sire breed matters as well because the lamb's own genes help trigger labour.

When can a ewe be scanned to see how many lambs she is carrying?

Between day 45 and day 90 after mating. Earlier than 45 days and litter counts are unreliable; much later and the lambs are too large to count on screen. Scanning results let you feed singles, twins and triplets separately, which is the single most profitable job in the whole pregnancy.

How much extra feed does a pregnant ewe need?

Almost nothing extra for the first 90 days, then a steep climb. In the last six weeks a twin-bearing ewe needs roughly 1.8 to 2 times her maintenance energy, and a triplet-bearing ewe more still. Underfeeding now causes twin lamb disease, small lambs and poor colostrum.

What are the signs a ewe will lamb tonight?

She leaves the flock, paws and circles a spot in the bedding, lies down and stands repeatedly, and her vulva is soft and swollen with the udder tight. A visible mucus string usually means the first lamb arrives within a few hours; if she strains hard for more than an hour with no lamb, examine her or call your vet.

More gestation pages

Livestock gestation chart