When Will My Ewe Give Birth?

Preparing for lambing is an exciting time, but can make many new shepherds very nervous too. Most births go smoothly, but there are many birth positions that the lamb can be in that requires intervention and assistance.

We use marking harnesses on our rams (see photo below) so that we can calculate each ewe’s due date. The harness has a slot at the chest to hold a crayon and when the ram breeds the ewe he rubs the crayon on her rump, transferring the color.


After 2 weeks (the length of the ewe’s cycle) we change the crayon to a darker color. If any ewes did not become pregnant in their first cycle they will ovulate again and the ram will breed them. Usually we change crayons until the ewes go a cycle with none being bred. This is often 2 -3 cycles, but it can depend on the number of ewes per ram, time of year, ram’s age and health (soundness), and nutrition or food available.

Sheep pregnancy is approximately 5 months, but various breeds of sheep have different gestation lengths. Tunis are generally pregnant for 150-152 days, but Icelandic sheep are only pregnant for about 145 days.

As lambing time draws near the ewe’s body will go through changes to prepare it for delivery and for nursing her offspring. The ewe’s vulva will swell and become brighter or darker. Her udder will also grow in size as her milk ducts prepare to produce colostrum and milk. A day or so before lambing the ewe’s water consumption will increase as her body makes colostrum. Her sides may “hollow out” as the lambs drop towards the birth canal. This may be drastic or barely noticeable, depending on how she is carrying the lambs and if her ligaments are stretched.

In this video, I point out these changes so you know what to look for and what looks “normal”. If you are unsure of anything, feel free to post questions. I would urge you, however, to contact your vet if anything seems amiss or (especially) if your ewe seems to need medical attention.