Karen Phillips, BVSc, MANZCVS: CHB Vets, Waipukurau
This article was first published in the magazine of the Black and Coloured Sheep Breeders’ Association, in June 2015. It is reproduced here with permission.
As lambing looms up it could be useful to cover a couple of topics that may be of interest.
The first is when to intervene and help a lambing ewe deliver her (hopefully) live lamb. Lambing ewes will choose a lambing spot up to several days before they go into labour, so moving ewes around at lambing time can disrupt this and lead to problems. Once a ewe has chosen a spot, which is often away from other sheep so she can have some privacy, she will return to it as she feels labour starting.
Keep an eye on ewes coming up to the start of lambing. You will notice the udders of the ewes closest to lambing will swell up as they fill with milk for their lambs, and the vulva swells and reddens. The early contractions are involved in getting the lamb/s into position for birthing and the cervix open and is known as 1st stage labour.
2nd stage is when the cervix is open and the uterine contractions are becoming more forceful with abdominal effort put in as well (‘pushing’) causing the water bag to come out and the lamb to be born. Once a ewe enters 2nd stage labour, a lamb should be born within an hour. If she is having multiple lambs there can be a gap of up to half an hour between the birth of each lamb. 3rd stage labour is when the placenta delivered.
There are no hard and fast rules for when to intervene and it is important to allow the ewe to lamb by herself if she can. If a ewe is straining, getting up and down and no lamb appears after half an hour, then intervention may be needed. It is important to have good hygiene standards when putting your hand inside a ewe as it is easy to introduce infection and maybe affect her chances of getting back in lamb in the future. It is also very important to be gentle as you are dealing with living tissue. The normal presentation of a lamb is with both front legs and the head presented as in the picture below. A breech or backwards presentation does happen and, as long as the lamb is born without unnecessary delay, should still produce a live lamb.
If you have assisted a ewe to give birth following good hygiene standards and she has been vaccinated with 5in1 before lambing, and the lamb is alive, then you shouldn’t need any antibiotic coverage after lambing. If you aren’t sure, ask your vet for advice. The best case is to let the ewe lamb by herself but sometimes you may need to help to ensure it goes well.
There are a few problems that can arise involving the udder of the ewe once she has lambed. An infection in the udder is known as mastitis and is more common in wet, muddy conditions as the bacteria enters up through the teat. Often the first sign seen is a dead or starving lamb before you notice any change in the ewe. This is a difficult condition to treat and control, but a good place to start is giving sheep enough room at lambing so reducing the time they are in muddy ground. Culling affected ewes can help as it tends to come back at future lactations. Another condition is known as hard udder where the udder appears to be full of milk and non-painful but no milk can be expressed. While there is no known cause for this it is thought to be linked to a spell of cold weather and a ‘chill’ in the udder or some other form of trauma. Affected ewes should be culled.
Lambing is a great time of year and is the time when everything comes together to produce our next year’s income. Enjoy this time.