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FurCalc

Sheep Pregnancy Calculator — Ewe Lambing Date (147 Days)

Calculate your ewe's lambing date using the standard 147-day sheep gestation (range 142–152). Pre-lambing vaccine and prep milestones included.

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Gestation: 142–152 days (avg 147).

Estimated lambing date
October 10, 2026
Window: October 5, 2026 – October 15, 2026
0%
Day
0 / 147
Week
1
Trimester
1
Day 0T1Day 147
1st trimester
d1–492nd trimester
d50–983rd trimester
d99–147
147 days remaining until expected due

Upcoming milestones

  • Confirm pregnancy
    Ultrasound or blood test confirms pregnancy.
    Day 30
    June 15, 2026
  • Fetal count ultrasound
    Optimal time to count lambs (1-3 typically).
    Day 60
    July 15, 2026
  • Increase nutrition
    Last 50 days = 70 % of fetal growth.
    Day 100
    August 24, 2026
  • Pre-lambing vaccines
    CDT (tetanus/enterotoxemia) 4-6 weeks pre-lambing.
    Day 120
    September 13, 2026
  • Move to lambing pen
    Clean, dry, observed area.
    Day 135
    September 28, 2026
  • Earliest lambing
    Monitor closely from here.
    Day 142
    October 5, 2026
  • Expected lambing
    Typical lambing day.
    Day 147
    October 10, 2026
  • Call your vet
    Overdue — check with a veterinarian.
    Day 152
    October 15, 2026
Dates are estimates. Individual pregnancies vary. Always confirm pregnancy and track milestones with a licensed veterinarian.

Frequently Asked Questions

How long is a sheep pregnancy?

Ewe gestation averages 147 days (just under 5 months), range 142–152. Meat breeds (Suffolk, Dorset) run slightly longer; hair sheep (Katahdin, Dorper) closer to 145.

How can I confirm a ewe is pregnant?

Ultrasound between day 35–60 confirms pregnancy and counts lambs. Pregnancy-associated glycoprotein (PAG) blood test works from day 30. 'Rumping' (visually observing wool loss on flanks and udder development) is less reliable.

What are signs of imminent lambing?

Udder fills 1–2 weeks before, vulva swells and softens 24 hours before, the ewe isolates, paws at ground, may bleat softly. First-stage labor lasts 2–6 hours.

When should I vaccinate my ewes?

CDT (Clostridium perfringens C&D + tetanus) booster 4–6 weeks pre-lambing provides colostral protection for lambs. Ovine ecthyma (soremouth) and bluetongue vaccines on farm-specific schedule.

Sources & References

  1. [1]
    Sheep gestation and lambing — University of Minnesota Extension
  2. [2]
  3. [3]

Common mistakes to avoid

  • Not testing for pregnancy toxemia — ewes carrying twins/triplets last 4 weeks need high-energy feed; missing this causes fatal ketosis.
  • Shearing pregnant ewes too close to lambing — stress. Shear 4-6 weeks before due date.

Pro tips

  • Separate ewes by due date for better lambing management.
  • Provide selenium/vitamin E if your region is deficient — prevents white muscle disease in lambs.