With grass in short supply, some might consider weaning earlier than usual to remove the ewe competition and provide more to the lambs. Twelve weeks is the optimum age to wean lambs, however some might wean earlier – it depends on the condition of the ewes and the availability of good quality pasture.
As the graph below shows, the contribution that milk makes to the lambs diet drops off from six weeks old. However, remember that milk is higher energy than most other feeds, so even a small proportion in mass is making a significant contribution in energy. Ewe condition and pasture availability (quality and quantity) is influential to this milk supply.
Figure: the transition from milk to grass in twin lambs (source: 400 plus, Beef and Lamb NZ)
As the lamb’s pasture intake increases, the ewe and lamb compete and the ewe will win the competition. Therefore the weaning decision should weigh up:
- The condition of the ewes – are they providing enough milk?
- The quantity of pasture – is competition restricting lamb intake?
Weaning before 12 weeks might be beneficial if ewes are in poor condition, i.e. not providing enough milk, and there is high quality pasture to put lambs on to.
Otherwise, wean at 12 weeks as this is when the milk supply to the lambs diet is low and you have the ability to prioritise the lamb nutrition over the ewes. In addition, the thin ewes can be prioritised over the fitter ewes to get on track target condition score at tupping time. Target minimum lamb weaning weight is 25kg, unless the lambs are being moved to high protein crops, such as red clover.
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