Lambing is the process of a ewe (female sheep) giving birth to one or more lambs. It also refers to the broader season on a farm when births are expected across the flock, typically lasting several weeks. For sheep farmers, lambing season is the most labor-intensive and critical period of the year, requiring round-the-clock monitoring, hands-on assistance with difficult births, and immediate care of newborns. The average sheep pregnancy lasts about 147 days, or roughly five months.
How Sheep Pregnancy Leads to Lambing
After mating, a ewe carries her lambs for around 147 days before labor begins. This timeline is remarkably consistent across most breeds, varying by less than a day or two depending on breed, age, and litter size. Older ewes (over five and a half years) tend to carry slightly longer, by about half a day to a full day. Farmers use the 147-day mark to calculate expected due dates and plan their lambing season accordingly.
A single ewe can carry one, two, three, or occasionally more lambs. Twins are common in many breeds, and the number of lambs born per ewe is tracked as the “lambing rate” or “lambing percentage.” The national average sits around 110%, meaning that for every 100 ewes, about 110 lambs are born. The American Sheep Industry sets higher benchmarks for well-managed flocks: up to 240% for small flocks of mature ewes, meaning some ewes are regularly producing twins or triplets.
The Three Stages of Labor
Lambing unfolds in three distinct stages, each with visible signs a shepherd learns to recognize.
Stage one is cervical dilation. The ewe becomes restless, circling, pawing at bedding, and lying down only to stand up again. Her vulva and udder swell noticeably, and a thick mucus discharge appears. This stage can last several hours as the ewe searches for a comfortable, private spot to give birth.
Stage two is active labor. It begins when the fluid-filled membranes appear at the vulva, signaling that the lamb is moving through the birth canal. In a normal delivery, the front hooves emerge first with the head resting on top of them, like a diver. Most ewes deliver within 30 to 60 minutes of the membranes appearing. If a ewe has been straining hard for longer than that without progress, something is likely wrong.
Stage three is the passing of the afterbirth (placenta), which typically happens within a few hours of delivery. Farmers watch to make sure this is expelled completely, since a retained placenta can cause serious infection.
When Things Go Wrong: Dystocia
Dystocia is the term for a difficult birth, and it’s one of the top causes of lamb death. The most common problems include:
- Malpresentation: The lamb isn’t positioned correctly. One or both front legs may be folded back, the head may be turned, or the lamb may come backwards with its hind legs tucked forward (breech). With twins or triplets, multiple lambs can enter the birth canal at the same time, tangling limbs.
- Size mismatch: The lamb is too large for the ewe’s pelvis. This happens most often when a ewe carries only one lamb and is overfed in late pregnancy, producing an oversized single.
- Poor dilation or weak contractions: The cervix doesn’t open fully, or the uterus doesn’t contract strongly enough to push the lamb out.
Shepherds learn to check the position of a lamb by hand and reposition it when possible. Knowing when to assist and when to call a veterinarian is one of the core skills of lambing season.
The First 18 Hours Are Critical
Newborn lambs face an immediate survival challenge: staying warm and getting their first meal. About 12% of all lambs die within the first three days of life. The leading causes are starvation combined with exposure to cold (accounting for 28% of those deaths), stillbirth (27%), and birth complications (13%).
Colostrum, the thick first milk a ewe produces, is essential. Lambs need between 180 and 210 milliliters of colostrum per kilogram of body weight during their first 18 hours. For an average 4-kilogram lamb, that’s roughly 720 to 840 ml, or about three to three and a half cups. This colostrum serves two purposes: it provides the concentrated energy lambs need to generate body heat, and it delivers antibodies that protect against infection. A lamb that misses this window has dramatically lower chances of survival.
If a ewe can’t produce enough milk, or if she rejects a lamb (which sometimes happens with first-time mothers or triplets), farmers step in with frozen colostrum reserves or bottle-feeding. In severe cases, lambs are tube-fed directly into the stomach.
Keeping Lambs Warm
Sheep are most comfortable between 45 and 70 degrees Fahrenheit, but newborn lambs are far more vulnerable to cold than adults. A lamb’s body temperature below 100°F is considered hypothermic, and hypothermia kills quickly in the hours after birth.
Farmers typically bring ewes close to lambing indoors so they give birth in a dry, draft-free environment. Individual pens (called “jugs”) keep the ewe and her lambs together for bonding and allow close monitoring. A thick layer of clean straw or shavings provides insulation from cold ground, and heat lamps are used for weak or small lambs. Towels and even hair dryers come into play when a lamb is born wet in cold conditions and needs to be dried fast.
What a Lambing Kit Looks Like
Experienced shepherds prepare a lambing kit well before the first ewe is due. The essentials fall into a few categories. For general use: long gloves (both examination and shoulder-length), antimicrobial soap, dry towels, a heat lamp, a halter for restraining the ewe, and a notebook for recording births. For difficult deliveries: lubricant, a head snare for pulling a stuck lamb, and leg snares. For newborn care: iodine to dip the navel and prevent infection, a scale and sling for weighing, scissors, ear tags, and frozen colostrum with bottles and nipples on hand for orphans or rejected lambs.
A thermometer is one of the most important tools in the kit. Checking a lamb’s temperature is the fastest way to tell if it’s in trouble, since a cold lamb that looks sleepy may be hypothermic rather than simply tired.
How Lambing Season Works on a Farm
On most farms, lambing doesn’t happen randomly throughout the year. Farmers control breeding by introducing rams to the ewes at a specific time, so that the entire flock lambs within a predictable window, usually spanning three to six weeks. This concentrated season means farmers can staff up, prepare facilities, and provide intensive oversight during the period when it matters most.
During peak lambing, shepherds check on ewes every few hours, day and night. Larger operations may run shifts. The work is physically demanding and sleep-deprived, but the payoff is direct: close monitoring during lambing is the single biggest factor in reducing lamb losses. Catching a malpresented lamb early, warming a chilled newborn, or matching an orphan with a foster ewe can mean the difference between a 12% mortality rate and something far worse.