Lambing is the term for parturition, or giving birth, in sheep. This natural process culminates the approximately five-month gestation period, which typically ranges from 144 to 151 days. The ewe’s overall health and preparation heavily influence the success of lambing. Understanding the distinct phases of lambing is important for flock management and ensuring the survival of both the mother and her offspring.
Recognizing the Signs of Imminent Lambing
A ewe displays distinct physical and behavioral changes 12 to 24 hours before the onset of active labor. The most noticeable physical change is the development of the udder, often called “bagging up,” as it fills with colostrum for the newborn lamb’s first meal. The vulva also becomes visibly softer, more relaxed, and slightly swollen as the birth canal prepares for delivery.
Behaviorally, the ewe exhibits increased restlessness, frequently getting up and lying down to find a comfortable position. This unease is often accompanied by pawing at the ground, a common nesting behavior to prepare a suitable spot for the birth. Many ewes will also seek isolation, separating themselves from the rest of the flock.
As labor approaches, the relaxation of the pelvic ligaments near the tail head becomes apparent, giving the rump a hollowed-out appearance. A thick, clear to whitish mucous discharge may be observed from the vulva, which is the remains of the cervical seal. These preparatory signs indicate the ewe is entering the initial phase of the lambing process.
The Three Distinct Stages of Lambing
The process of lambing is divided into three sequential stages, each defined by specific physiological milestones. The first stage, known as cervical dilation, begins with uterine contractions that are not yet visible as active abdominal straining. During this phase, the ewe appears uneasy, frequently shifting position, or looking towards her flank. This stage typically lasts between two and 12 hours, with first-time mothers sometimes taking longer.
The purpose of the first stage is the softening and complete dilation of the cervix, which is achieved through the pressure of uterine contractions. Hormonal shifts, particularly the fetal release of cortisol, help stimulate these contractions. The end of this stage is marked by the rupture of the allanto-chorion, the first fluid-filled sac, often called the breaking of the first water bag.
Stage two is the active phase of fetal expulsion, characterized by strong, forceful uterine and abdominal contractions where the ewe is visibly straining. This stage begins once the cervix is fully dilated and the lamb is forced into the birth canal, usually presenting with the two front feet and the head resting between them. For a single lamb, this stage should be completed within 30 minutes to one hour after the start of active straining. If the ewe is carrying multiple lambs, the sequence is repeated for each lamb, with an interval of 10 to 60 minutes between births.
The third stage is the expulsion of the placenta, often called the afterbirth, which occurs after the delivery of the last lamb. Uterine contractions continue, though less intensely, to detach and expel the fetal membranes from the uterine wall. The placenta should be passed naturally within two to eight hours after the birth of the last lamb. If the placenta is not expelled within 12 to 24 hours, it is considered retained and requires careful monitoring.
Essential Post-Lambing Management
Immediate management following the third stage ensures the health of both the ewe and her newborn. The ewe should immediately begin licking the lamb, which cleans the newborn, stimulates circulation, and initiates maternal bonding. Ensuring this bond forms without interruption is important, as a strong connection reduces the risk of the ewe rejecting her offspring.
The most time-sensitive action for the lamb is consuming colostrum, the ewe’s first milk, which is rich in energy and protective antibodies. A lamb must consume 10 percent of its body weight in colostrum within the first six hours of life to gain passive immunity. If the lamb is too weak to suckle, the colostrum must be administered via an esophageal tube.
Another immediate step is dipping the lamb’s navel cord in a suitable antiseptic, such as a seven percent tincture of iodine, soon after birth. This practice prevents infectious organisms from traveling up the umbilical cord into the bloodstream, which can lead to serious navel and joint infections. The ewe’s postpartum health also requires monitoring for complications, such as excessive hemorrhage.
The ewe’s nutritional needs dramatically increase after lambing as she enters peak lactation to support the lamb’s rapid growth. She requires high-quality feed with increased energy and protein content to sustain milk production and recover her body condition. Close observation of the ewe and lamb pair for the first 72 hours confirms successful nursing, bonding, and overall well-being.