Last week, we covered the nutritional needs of heavily pregnant does. This week we discuss minerals and vaccines for ewes in late pregnancy.
The ewe needs sufficient quantities of calcium, phosphorus, magnesium and certain amounts of trace elements (manganese copper, zinc, molybdenum, selenium, iodine and cobalt), to provide for the growing lamb, to make sure there is a solid foundation for strong bones and to deliver a healthy, disease-free lamb.
Dr Johan van Rooyen of the Grootfontein Agricultural Development Institute says: “If you’re not giving supplementary feed to your pregnant ewes, you should at least provide a mineral lick. They are usually called phosphate licks, but read the label carefully and make sure you are getting the other minerals and trace elements.”
A good size for a lamb is a little more than 3.5kg at birth. The uterus, placenta and fluids weigh about 1kg, which gives you an approximate total of 5kg. So, the single- (one lamb) carrying ewe should pick up at least 5kg in the last six weeks of pregnancy.
As a rule of thumb, a twin-carrying ewe needs to pick up 10kg, and a triplet-carrying mother should gain 15kg.
It’s good practice to mark 10 or 15 ewes from each flock and weigh them every week for the last six weeks. If you can go the extra mile do it for the last eight weeks. Work out the average weight and plot the trend on a simple graph. This will help you to monitor growth and tweak your feed accordingly.
After giving birth, the ewe will need about double the quantity of energy to produce milk. If she has not stored any fat during pregnancy, she will not have enough reserves for milk production and she will lose weight. “Ewes simply cannot eat enough in a day to produce all the milk the lamb needs, and she has to use her fat reserves. It is very important to help your ewes build up good fat reserves during late pregnancy,” says Van Rooyen.
This is a principle every stock manager must understand so I am going to say it again. Immediately after the mother has delivered her lamb, she will put everything she has into milk production. It’s a situation where output is greater than input, because, no matter what she is offered she cannot take in enough to meet the demands of the lamb and her own maintenance needs.
Condition will drop, it’s inevitable. However, if you have taken care of your ewes in late pregnancy the condition will pick up reasonably quickly. Animals in poor condition will not reconceive, animals in good condition will. It’s your call – so make it a sensible one.
Ewes must be vaccinated four to six weeks before lambing. They need protection against diseases that could harm them at lambing or afterwards.
After a difficult birth ewes may develop gangrene of the uterus as clostridial bacteria (Clostridium septicum) reproduce rapidly in bruised and torn uterine tissue. The toxins produced by the bacteria kill the ewes. The danger of the bacteria affecting other ewes increases when ewes lamb in pens or small camps.
Pasteurella organisms are a common cause of mastitis.
Van Rooyen advises boosting the ewe’s immunity to pulpy kidney (also a clostridial disease) before starting her on concentrates.
Pulpy kidney can only be controlled through vaccination. Vaccinate the lambs of vaccinated ewes from 3 months onward, or vaccinate them at weaning. All clostridial vaccines must be boosted after a month (3 – 4 weeks) and then administered every year. Covexin 10 and Ovivax 6 are good options to choose.
Vaccination is increases the antibodies the ewe passes onto the lamb through the colostrum (or first milk). These antibodies should protect the lamb against diseases like lamb dysentery, pulpy kidney and Pasteurella pneumonia.
To quote Dr Alex Niven, ‘if you want healthy young animals that will grow into healthy productive animals, make sure they get colostrum as soon as possible after birth. And make sure it’s decent colostrum’.