Ewes generally lamb around 145 days after mating. Some of course will be earlier & some later, but 145 days is the norm.
For a successful lambing, ewes need to receive good nutrition, particularly in the last month of pregnancy when the lamb will approximately double in size. It is at this time that the ewe will also begin to develop her milk supply. On the other hand a ewe that is too fat could experience trouble lambing. If the ewe receives too much feed, especially in the last month prior to lambing, the lamb may grow to be of an exceptional size which could cause problems at birth.
When ewes are due to lamb it is a good idea to move them to a sheltered paddock and one that is close at hand so that you can check on the regularly. Make sure that all ewes are clearly identified with eartags that you can read (binoculars are good for this) or with their number branded on their side.
In order to survive a new born lamb must :-
Lambs that have experienced a difficult birth and therefore been deprived of oxygen for even a short time will be “flat”. That is it will take them longer to get to their feet. Likewise lambs born into extremely cold, wet and windy conditions will lose body heat very quickly and unless they get to their feet extremely quickly and have a drink straight away will soon not have the energy to suckle properly if they do manage to get to their feet. In such cases it may be necessary to bring the ewe into a sheltered yard, warm the lamb/s and start the lamb/s drinking.
If a ewe requires assistance, choosing the correct time to intervene is important. Only experience can really help you. However it should be obvious if there are problems due to mal- presentation of the lamb. If the lamb is badly presented it is best to run the ewe into a yard, catch her and help out as soon as possible. You will have more likelihood of delivering a live lamb if you don't leave it too long. It is also much easier to help a ewe in difficulty when she is fully dilated, lubricated still able to help you. If you leave it too long to step in and help out, not only will the lamb will be dead but the ewe will be exhausted and of little help to you in pushing the lamb out.
The correct presentation for lambing is front first. The water bag (a dark round bulge) should break and be followed by two feet and a nose resting on top of the feet. The birth process will vary from one ewe to another, however if all is well, birth should occur within 45 minutes of the appearance of the lamb's feet and nose.
Common Forms Of Mal-Presentation
Some common forms of mal-presentation are listed along with possible solutions.
It is important to keep the risk of infection to a minimum so cleanliness is essential. Wash your hands and arm in pure soap (which can also act as a lubricant) or Betadine solution. Do not use harsh detergents or other soaps which may burn or irritate the ewe. If you have them use disposable rubber gloves and a personal lubricant (excellent to keep on hand for such emergencies). When you have finished, it may also be a good idea to give the ewe a course of penicillin to ensure that you do not lose her to infection.
One leg back
Quite often gentle pulling whilst the ewe is pushing will assist the birth of a small or normal sized lamb in this position. If no progress is made, check that the legs and head belong to the same lamb. To do this you will need to put your hand right into the ewe and feel to see if you can find only one lamb.
Usually the lamb can be delivered by taking hold of the leg that is visible with one hand and using the other grasp the neck as close to the shoulder as possible. Pull the lamb. If not successful at first try turning the lamb one way then the other as you pull. Try to turn the shoulder which is caught, towards the top of the pelvis first. Considerable pressure can be exerted without harmful effects. If you fail, tie string around the lower part of the visible leg, just above the hoof, tying off at the back of the leg. Then double the leg back under towards the shoulder and push the leg back trough the pelvis. Now try to locate the other leg by pushing your hand along the neck of the lamb and through the pelvis as far as necessary. The leg will be back along the lamb's body. Use a finger as a hook, hooking the leg at the knee joint. Drag the leg forward through the pelvis. Usually the knee joint can be induced to move forward for “hooking” by putting the fingers under the shoulder blade and pulling it forward. When the leg is out, bring the other leg forward by pulling it with the attached string, using an upward pull towards the back bone for best results.
If the missing leg cannot be brought forward or will not come through the pelvis, tie string around the lamb's head behind the ears with the knot under the head. Push the head back into the pelvis along with the leg that had been showing initially. Maneuver the missing leg into position and use the strings attached to the lamb's leg and head to get the lamb into the correct position for birth. When the lamb is in the correct delivery position assist the ewe with the delivery of the lamb.
When using more than one string it is a good idea to use some method of identifying the different strings such as tying a knot in the end of one and a loop in the other.
Two legs back
Use the preceding method of getting the legs forward by “hooking” the knee with your finger as described above.
One method is to put the visible leg or legs back through the pelvis and move the lamb's head and hind legs into the normal presentation position. Leave the lamb for ¾ hour to an hour and she will usually have the lamb herself or push it into a more accessible position.
Another method is to tie string on the available leg or legs, push them back trough the pelvis and then work the head through the pelvis by either using the thumb and forefinger to grasp the lower jaw and pull the head through, or with a noose around the back of the head and tightening in the mouth. This is a difficult exercise which ever method you choose. Once the head is through bring the legs through with the attached strings. Often you may be able to bring a leg or even both legs through as you maneuver the head through the pelvis.
Breech birth – back to front delivery
A ewe with a breech lamb will often not get down to serious lambing as other ewes do but rather will be noticed squatting frequently as if trying to urinate. Close examination will reveal back legs, a tail or maybe part of the backbone being presented first.
Sometimes it is difficult to know if it is a front or back leg or legs presented first. A hind leg has the front of the hoof corresponding with the direction in which the hock can be bent. Whereas a front leg has the back of the hoof corresponding with the direction in which the knee joint can be bent.
When delivering a lamb in the breech position care must be taken as:-
If only the backbone or tail are presented push the buttocks forward and ease one leg at a time up and over the brim of the pelvis in a flexed position. Grasp both hind legs in your hand with the hooves resting in your hand and deliver the lamb with a solid even pull, tending to pull slightly upwards towards the ewe's backbone as you do so. Take care as the shoulder and ribs are coming through the pelvis. If you can get your finger behind the shoulders to assist with the passage all the better.
Quickly clear the mucus from the lamb's throat by holding the lamb by the hind legs with the head hanging down. If necessary swing the lamb in a circular motion to aid in the clearing of mucus from its airways and to facilitate commencement of breathing.
It is of decided advantage to have another person assist you with a breech birth delivery. To have someone holding the ewe makes your job easier and increases the chances that the delivery will be successful.
Roll the lamb over to be as near to the normal delivery presentation position as possible. Then use the most suitable of the above methods to deliver the lamb.
Twins coming out together.
There are many possibilities. The most common is the hind legs of the second twin presented with the front legs or head of the first twin. One twin, usually the one coming backwards, should be pushed back allowing the other twin to move ahead and be delivered first. However the primary rule is to deliver the twin that requires the least maneuvering first. Take your time and work carefully and slowly.
Abnormal births that require veterinary assistance.
In complicated births where you feel out of your depth, work no longer than 15 minutes before you seek professional assistance. Such situations may include abnormally large lambs (requiring a caesarean), dead lambs which may be swollen (requiring some dismembering), twisting of the uterus, uterine inertia (labour contractions are weak) and deformed lambs.
Remember that a ewe needs assistance if she can't deliver her lamb/s after 45 minutes of serious effort. Once it is obvious that assistance is necessary, try to size up the situation quickly and decide if you can cope or not.
If a vet is needed, call him/her early - don't expect the vet to be able to perform miracles after you & the ewe are thoroughly exhausted.
Other Problems related to lambing.
Retained after birth
The placenta is usually passed within one hour of lambing. It must be removed within 12 hours of lambing because by then the neck of the womb has mostly closed.
Don't pull on the afterbirth and try and remove it physically as this will cause excessive bleeding. If long pieces of afterbirth are hanging out and are in danger of being trampled on by the ewe, the pieces hanging down can be cut off at the level of the hocks. Daily treatment with foaming pessaries will prevent infections and the ewe can be left for 3 to 4 days to eject the afterbirth on her own, or allow the afterbirth to loosen before steps are taken to remove it. When pessaries are placed into the uterus, the membranes can be lightly pulled ("milked"), but tearing must be avoided.
Uterine pessaries can be put into the uterus until the cervical opening closes. If the afterbirth is not expelled after 3 – 4 days it is time to seek veterinary advice.
Metritis or infection of the uterus is common after a difficult birth and retained afterbirth. The “normal” discharge from the ewe after lambing is thick and dark reddish- brown. It start a few days after lambing and lasts for two to three weeks before it clears up without treatment. However, if the discharge is a different colour, is purulent (pus) or has a smell and the ewe is ill (off her feed feverish and down in milk production) call the vet.