Learn to Raise Sheep
Introduction: Terminology and Breeds
Selection and Breeding
Nutrition of sheep
Diseases in sheep
General management of commercial flocks
Care of lambs
The marketing of sheep and sheep products
Sheep are only as Good as What they Eat
If you want to optimise the health, wellbeing and productivity of sheep, you need to apply a more refined management than simply letting them graze in any available paddock.
Feed Requirements for Rams
Young, actively growing rams need considerably more nutrients than the mature ram. The young ram should be given a ration that is relatively high in protein to promote the development of muscle but not fat. He will also need adequate amounts of phosphorous and calcium for the development of sound bones. Concentrates that are high in energy should be avoided as, apart from laying down fat, they suppress sexual maturity. Green pastures are very beneficial to young rams but must be supplemented if there are local mineral deficiencies.
The mature ram needs to be fit and active for the breeding season. Six weeks before the season starts, introduce a concentrate feed as shown in the following example:
- 40% maize
- 40% oats (grain or rolled)
- 20% wheat bran
The amount of concentrate fed should be increased gradually from 0.2 kg to 0.5 kg per day.
Feed Requirements for Ewes
Empty ewes (ewes that are not in lamb) require only a basic maintenance ration. A maintenance plus production ration would be required by the following:
- Shortly before the ewe goes to the ram. The practice of giving ewes extra food for two weeks before they go to the ram is called flushing. It is done to improve the conception rate of the sheep and to increase the chance of twins.
- Lactating ewes, rearing a lamb. Ewes that are rearing twin lambs will require more food than those rearing a single lamb.
Feeding of ewes can be divided into the reproduction stage and the lactation stage.
Reproduction Stage - Flushing
Flushing is given to ewes in poor condition to enable them to gain mass. If flushing is successful, it will result in the production of more ova (eggs), improved conception and a higher lambing percentage. Examine the ewes six weeks before mating and separate those that need flushing. Flushing can be done in several ways:
- move the sheep to fresh pasture
- reduce stocking rates
- feed a legume hay
- feed maize silage
- feed a high energy concentrate at the rate of 200 to 450 g per day if pasture is scarce
Feeding the Ewe after Joining
There are 21 weeks of gestation and these can be divided into two periods; the first 15 weeks and the last 6 weeks. Incorrect feeding is the cause of most foetus losses in the first month of pregnancy. Therefore, it pays to continue "flushing" the ewe for 21 days after mating to keep her in good condition. The next two months of pregnancy is a time of rapid growth of the placenta (the wall of the womb) while the actual foetus does not grow much at all. The aim is to provide only enough energy for a small average body weight gain of 30 g/day (for a 60 kg ewe). Fat ewes should be rationed to avoid problems at lambing. At this stage, a good pasture would provide all the ewes need.
The foetus grows most rapidly in the last two months of pregnancy. This leads to a dramatic increase in the energy and protein needs of the ewe. A concentrate should be introduced six weeks before lambing is due. Start by giving 100 g/day and work up to around 350 g/day. At this stage, the lamb will be taking up a lot of room in the ewe and she will not be able to eat much bulky feed (grass, hay or silage).
Ewes that do not receive enough food at this late stage of pregnancy are susceptible to pregnancy toxaemia (ketosis or "domsiekte") in which body fat is broken down to supply the much-needed energy. Over-fat ewes, by contrast, will produce overly large single ewes, will have a difficult birth and the uterus will take a longer time than normal to recover. As a general guide, pregnant ewes should show a 15% increase in body mass from mating to lambing.
Lactation Stage - Feeding the lactating ewe
The first two months of lactation cause a dramatic increase in the nutritional needs of the ewe. Lush, cultivated pasture can supply the needs of the ewe at this stage but anything less than this should be supplemented with a concentrate. The concentrate should not be cereal but rather grass-cubes, lucerne meal, brewers' grains or sugar beet pulp. This is because the ewe needs acetic fermentation in her rumen to produce milk (rather than the propionic fermentation that cereals produce). Ewes feeding twins and triplets require approximately 30% more feed at this stage.
Feed Requirements for Lambs
During the first month, the lamb relies on milk from its dam. The more milk the lamb consumes the more mass it will gain. The newly born lamb starts its life adapted to digesting and utilising milk. The nutrients in milk are highly digestible and easily absorbed by the lamb. The lamb only develops into a true ruminant when it begins to pick at roughage such as hay or grass. The intake of roughage stimulates the development of the compound, ruminant stomach.
Lambs can be introduced to a creep feed at three weeks old. Pre-weaned lambs are able to convert feed much more efficiently than a mature sheep. For example, the average feed conversion of the lamb varies from 3:1 to 4:1 which means that the lamb is gaining 1 kg for every 3 to 4 kg it is fed. The idea of “creep feeding” is to take advantage of this superior feed conversion.
Initially, creep feed is given to lambs ad lib. It should be kept out of reach of the ewes. The feed must be palatable (for example, soybean oilcake, good-quality lucerne or oat seed). As much home grown feed stuffs as possible should be included in the creep feed to reduce costs. A typical creep feed is:
- 15% chaff hay
- 68% maize meal
- 5 % bran
- 13% high protein concentrate
Alternatively, the following can be given:
- 17% lucerne chaff
- 72% maize meal
- 10% high protein concentrate
Lambs can be weaned at 6-8 weeks of age for fattening off the ewe. The lambs should weigh about 15 kg at this stage. The following table shows the amounts of concentrate and silage they should receive from weaning to slaughter at 40 kg.