Lambing Season Prep: The Complete Checklist

Lambing season is the most important four to six weeks on a ewe-lamb operation. What you do in October — vaccinations, body condition, pen prep — determines what you are chasing at 2 a.m. in February. This guide is a working checklist organized by timeline: what to do 60–90 days out, 30 days out, two weeks out, and once lambs are hitting the ground.

Know your lambing dates first

Before anything else on this checklist, run your breeding dates through the sheep gestation calculator so you know when each group is expected to lamb. A 146-day Suffolk ewe and a 148-day Merino bred on the same day do not hit the same window. Get dates on the board before you prep anything else.

For breed averages, gestation factors, and monthly planning tables, see our sheep gestation period guide.

60–90 days before lambing starts

Sixty to ninety days before your first expected lamb is when you set the table. Vaccinations, body condition, and late-gestation nutrition all need lead time. If you wait until pens are full of close-up ewes, you are fixing problems you could have prevented.

Vaccination program

CDT (Clostridium perfringens types C & D + tetanus) pre-lambing booster: give 4–6 weeks before lambing so ewes pass antibodies in colostrum. First-time ewes need the primary series earlier — two doses 3–4 weeks apart, with the booster at 4–6 weeks pre-lambing.

Work with your veterinarian on regional disease pressure. OPP, CL, and sore mouth may be in your vaccination protocol depending on your state and marketing requirements.

Internal parasite (FAMACHA) check — ewes in late gestation are more susceptible to barber pole worm. Run FAMACHA scores if you are in a high-risk region, especially the Southeast. Do not blanket deworm — resistance management matters more than a quick fix.

Body condition scoring

Target BCS 3.0–3.5 for mature ewes at lambing. Thin ewes (BCS below 2.5) produce less colostrum and have higher lamb mortality.

Sort thin ewes now and feed separately. You cannot condition-score a ewe into shape in the final 30 days. Ewe lambs (first-time mothers) need extra feed — they are still growing themselves while carrying a pregnancy.

Nutrition planning

Roughly 70% of fetal growth occurs in the final 6 weeks. Energy and protein demands spike sharply in that window.

Have hay tested. Do not assume last year’s stack is the same quality. A bad test you ignore in November costs you in February.

Begin flushing (increasing grain) at 4–6 weeks before lambing: 0.5–1.5 lb/day depending on body condition and expected litter size. Confirmed multiples need the upper end.

Selenium: In selenium-deficient soils (most of the US), ewes need supplementation. White muscle disease in lambs is preventable with a BoSe injection around day 120–130 per your veterinarian’s protocol.

30 days before lambing starts

Thirty days out is facilities, equipment, and making sure nothing fails at 2 a.m.

Pen inspection and setup

Walk every lambing pen, gate, and head catch. Fix now, not when a ewe is halfway through the chute.

• Minimum 16–20 sq ft per ewe in a lambing pen. Crowded, muddy pens are where hypothermia and navel ill start.
• Clean and bed deep with straw. Straw insulates better than hay bedding.
• Check all lights. Buy backup bulbs. Hypothermia kills fast — lambs do not send a warning.
• If you run cameras, test signal and battery now.
• Stockpile extra bedding close. You will use more than you expect.

Equipment checklist

Build a physical checklist and tape it inside the barn door.

• Lamb puller (if used)
• Obstetrical lubricant and arm-length sleeves
• Esophageal tube feeder for lambs
• Lamb feeding bottles and nipples
• Flashlights and headlamps with fresh batteries
• Ear tags, tagger, and marking crayons
• Thermometer
• Scale or weight tape
• Iodine (7% tincture) for navel dipping
• Lamb warming box or heat lamp

Build your lambing kit

One container, lambing area accessible. Include your vet’s phone number on a card inside the kit — not just in your phone contacts. Hands are dirty when you need it most.

At minimum: lube, sleeves, gloves, flashlight, iodine, tube feeder, colostrum replacer, electrolytes, feeding bottle, and the vet card.

Two weeks before lambing starts

The last two weeks are colostrum planning, ewe movement, and making sure everyone checking sheep knows what normal labor looks like.

Colostrum management plan

Colostrum is non-negotiable. A lamb that does not receive enough colostrum in the first 6–8 hours has severely impaired immunity.

Target 10% of body weight in colostrum in the first 4 hours. A 10-lb lamb needs roughly 150–200 ml (5–7 oz). Get it in within 2 hours if the ewe will not mother.

Have colostrum replacer on hand — not supplement. Replacer stands alone; supplement is additive only.

Freeze quality colostrum from high-producing ewes if your operation allows. Label with date. Thaw in warm water — never microwave.

Storage rules worth posting in the barn:

• Refrigerate colostrum up to 24 hours
• Freeze for up to 12 months at 0°F
• Thaw in warm water only

Moving close-up ewes

First-time ewes: Move to a close observation area 3–4 weeks before their first expected lambing date.

Experienced ewes: Move to a close lambing pasture 1–2 weeks out.

Rotate ewes to clean lambing pens every 10–14 days to reduce scours and navel ill exposure for younger lambs.

Know the signs

Review the three stages of labor with everyone on the schedule.

1. Stage 1: Restlessness, separating from flock, nesting, pawing, loss of appetite. Can last 2–6 hours.
2. Stage 2: Active straining, water sac visible. Lambs should arrive within 30–45 minutes of active pushing for singles; allow slightly more time for multiples. If longer with no progress, assist.
3. Stage 3: Placenta expulsion. Should pass within 1–2 hours. Retained placenta beyond 4–6 hours — call your vet.

Tail ligament check: When you can no longer feel the ligaments on either side of the tailhead, lambing is typically within 12–24 hours. Check daily starting 1 week before due date.

During lambing season

Once lambs are hitting the ground, the job shifts to observation, the first hour after birth, and staying ahead of hypothermia and mismothering.

Observation frequency

• First-time ewes: Check every 2 hours around the clock during peak lambing window.
• Experienced ewes: Every 3–4 hours. Night checks are non-negotiable in cold weather.
• A wet 8-lb lamb at 28°F can be hypothermic within an hour.

The first hour after birth

1. Clear mucus from nose and mouth if the ewe has not — first-timers sometimes need help.
2. Check the lamb is breathing and attempting to stand.
3. Dip navel in 7% iodine within 30 minutes. Every lamb, every time.
4. Watch for nursing within 1–2 hours. A lamb that stands but does not suck needs intervention immediately.
5. Weigh when possible. Birth weight drives your colostrum volume target.
6. Record: ewe ID, lamb ID, birth weight, litter size, colostrum status, any problems.

Hypothermia response

Lamb rectal temp below 101°F = hypothermia. Warm in a lamb warming box or tub of warm water (support the head). Give warmed colostrum by tube feeder once temp reaches 101°F.

Do not tube feed a hypothermic lamb — it cannot absorb nutrition at low body temperature.

Mismothering and bottle lambs

First-time ewes reject lambs more often than experienced ewes. Intervene early — every hour without colostrum is a risk.

Use a jugging pen — confine ewe and lamb together in a small pen for 24–48 hours. Most ewes bond in this window. If she will not accept after 48 hours, she is a bottle candidate.

Keeping records

Minimum to track per pair:

• Ewe ID and breeding date
• Expected lambing date (from the calculator)
• Actual lambing date
• Lamb ID and birth weight
• Litter size
• Colostrum status
• Any problems

A whiteboard works. What does not work is trying to remember in April which black-face ewe had triplets.

The producers who have the smoothest lambing seasons walked through every checklist item before the first ewe broke water. Lambing season is managed in the fall so it is predictable in February.

If you also run cattle, our calving season prep checklist follows the same timeline structure for beef operations.

Lambing season FAQ

What is the lambing percentage I should expect?

Commercial flocks often target 150–180%. Prolific breeds can exceed 200% with good management.

How do I prep for a ewe with triplets?

Ultrasound at day 30, extra flushing, jugging pen ready, bottle-feed plan for the weakest lamb.

What is the biggest cause of lamb death in the first week?

Inadequate colostrum in the first 6–8 hours, followed by hypothermia and scours.

When do I intervene during labor?

30–45 minutes of active straining with no progress on a single. Call your vet if you are unsure during an assist.

Should I dock tails and castrate, and when?

Common in the first week when weather is dry and lambs are nursing well. Follow your vet and market requirements.

Further reading

• Sheep Gestation Calculator
• Sheep Gestation Period Guide
• Calving Season Prep Checklist — if you also run cattle
• Farm Loan Calculator — expanding your flock