Lambing is a stressful but rewarding time of year and as 2022 starts, vets start to prepare for “spring”, our busiest time of year. This article aims to give you advice on stage 2 of parturition; delivery of the foetus. The focus is on ewes, but many of the same principles apply to cows.
Stage 1 – The ewe may become restless and separate herself from the flock, as her cervix dilates in preparation for birth, and a string like mucus is expelled from her vulva. This stage usually lasts for 2 – 6 hours.
Stage 2 – A water bag will protrude out of the vulva and should rupture quickly. The ewe will lie down as she starts to push and front limbs of the first lamb protrude, followed by the head until the entire new-born is delivered. This stage typically takes less than an hour however, varies from 30 minutes to two hours. For ewes with multiple lambs, we expect approximately 20 minute intervals between siblings.
Stage 3 – The placenta and foetal membranes should be expelled within two to three hours after giving birth. Ewes will often eat their placenta, this is completely normal and is a good source of nutrients. If a ewe doesn’t expel her placenta within 12 hours it is considered retained.
Dystocia is a medical term, meaning “Difficult birth, typically caused by a large or awkwardly positioned foetus, by smallness of the maternal pelvis, or by failure of the uterus and cervix to contract and expand normally.”
Normal foetal presentation is the forefeet first, with the head between them (nose first). The spine should be facing the sky. Dystocia often occurs because of large singles or due to the ewe being too narrow. If assistance is needed then lubrication is essential and if lambing ropes are to be used, ensure they are properly looped around each leg above the fetlock joint. Determining the front legs from the back legs is best done by bending them gently. The front legs bend the same way, forming a C-shape, the back legs bend in opposite directions, forming a Z-shape.
Head snares/ropes MUST be placed properly (orange line on image).
They should be placed behind the ears and follow the jaw to the mouth. If placed round the chin, this may cause strangulation or damage to the spine. If placed above the mouth this is likely to slip off.
Most abnormal positions require correcting into the normal birthing position before delivery. These are shown in the table below.
With any of these abnormal positions, the use of lube and correctly placed lambing ropes are essential to ensure proper and safe delivery. If you have any doubts or concerns, we are on call 24/7, 365 days a year so please give us a ring on 01722 333291.