This fact sheet was developed by students enrolled in Purdue's ANSC 442 Sheep Management course in Spring 2003, as a semester project. These fact sheets provide useful information on various topics related to sheep. View the list of fact sheets.
Lambing from A to Z
So your Ewe is pregnant ... Now what?
Early Gestation The first part of the fetal development. The nutritional needs are very high quality forages and grains due to the fact that she is developing one or more feti. During this time, the bones and muscular system is being formed for the young.
Mid-Gestation During this phase is pregnancy the ewe's nutritional needs are still pretty high. This is for the future of milk production and growth of the feti. This is the time that you can ultrasound the ewe to see how many she is carrying and to double check that she really is pregnant.
Heading towards the outside world Since the gestation length of the sheep is 140-145 days you can begin to look for signs that the little one will be coming as early as 135 days after you bred her.
The Normal Birth Process
First Stage of Labor (cervical dilation) - The first stage of birth consists of uterine contractions and cervical dilation. It may last anywhere between 2 and 14 hours. The ewe may be uncomfortable, but is not yet fully straining to deliver the lamb. She may exhibit behavioral changes such as isolating herself, pawing to create a nest, and acting uneasy.
Second Stage of Labor (expulsion of the lamb) - The lambs feet or head entering the vagina induces the second stage of labor, which is actual labor and delivery. The ewe will use abdominal contractions and actively work to expel the fetus. It is normal that a ewe will pass her water bag prior to delivery. This stage should take no longer than 1 - 2 hours, but it is suggested that you check the ewe if delivery has not yet begun after 40 - 60 minutes after the water bag appears.
Third Stage of Labor (expulsion of membrane) - The third stage of labor is when the animal expels the afterbirth.
Normal Position of the Lamb
|The correct presentation of a lamb is when the front feet emerge first with the muzzle nuzzled in between them (a diving position). The lamb should be in an upright position with its nose inline with the ewe's spinal column.|
When does the ewe need assistance?
What steps do I need to take?
Isolate the animal: Once you have determined that the ewe may be experiencing problems you should try to get her in a relatively clean area, where her movement is limited, and other animals will not get in the way. It may be a good idea to have someone restrain the animal, if possible. You can assist the ewe while she is standing, but should be prepared for her to lye down.
Be Clean: Clean the area around vaginal opening and wash your hands thoroughly prior to the examination. It is recommended that you where a sleeve glove to protect yourself (especially women) from reproductive diseases commonly found in sheep.
Lubricate: Lubrication is very important and you can not use too much! Failure to lubricate the birth canal may cause tissue damage and undoubtedly a very difficult birth.
Check for dilation: When you enter the vagina keep your fingers close together so that you do not injure her reproductive track. Find your way to the cervix and determine if the ewe is dilated. If she is not fully dilated, you can give her more time and gently run your hand around the cervix to expand the opening. If the ewe does not progress toward dilation you may need to call a veterinarian for assistance.
Determine presentation of fetus: If dilation has occurred, the next step is to palpate the fetus to establish its presentation; that is if it is facing forwards or backwards. Compare what you are feeling to the anatomy of the ewe to distinguish between front and back legs. Also make sure you follow the legs to the body to ensure you are working with one lamb and not two.
Determine posture of fetus: Next you want to determine how the legs and head are positioned, the posture of the lamb. Visualize the normal presentation of the lamb as you think about what parts you are feeling.
Pull: If everything is normal you can proceed by gently pulling the forelegs legs of the lamb in a downward motion. With your help the ewe should be able to give one final push and you will hopefully have a healthy new lamb.
Double check: Be sure to feel for remaining lambs when the ewe stops exhibiting labor behavior.
Causes of Dystocia (a difficult birth)
Tight squeeze: There are many different problems that could occur during parturition, the most common problem seen in sheep is having a fetus that is to big to pass through the pelvis of the ewe. Firm pressure can be used as in a normal birth, but if delivery is not successful you can roll the ewe onto her back for delivery. If the lamb is still to big you should call for veterinary assistance. Your veterinarian can help you decide if a caesarian section is necessary.
Malpresentation of the fetus: This is when the lamb is not in the correct position. There are several forms that are fairly common and are a likely cause of dystocia.
One or both legs back:
|The situation where only one leg is retained is a common problem. It can usually be solved by either pulling the lamb in that position, if there is enough room, or by pushing the body back far enough to get a hold of the leg and pull it forward for a normal position.|
When both legs are positioned backwards and the head is the only thing in the birth canal you have a more serious problem. Usually it is very difficult to push the head back in and attain a normal birthing position. In this situation you can try to assist, but should get assistance promptly, if your efforts are unsuccessful.
Front legs only, head back
|This is a very difficult malpresentation to deal with and requires patience when positioning the lamb correctly. You must gently search for the head and bring it into the correct position. A snare may be useful in holding limbs in place.|
|In a breech position the animal is facing the wrong direction and both feet are facing forward. To deal with this case, you need to push the lamb forward and grasp one of the rear legs gently pulling it into the birth canal. Follow with the second leg. Be careful not to puncture the uterine lining with the toes. If lambs are situated a similar position, but feet are facing backwards, it is not a breech position. Lambs can usually be pulled in a backwards fashion with no problems, but pull gently, because the ribs are susceptible to breaks.|
For more information visit these websites:
Diagrams provided by Utah State University: http://extension.usu.edu/publica/agpubs/ah/sheep11.pdf
Lambing: What to do afterwards
Project done by: Amy Bergstedt, Lindsey Crosby, Sarah Shaffer Spring 2003
"Care of the Newborn lamb"
"Newborn lambing management" Virginia Cooperative Extension
Management Guidelines for the efficient sheep production.