Early weaning is likely to be on many of our sheep farmers radars this year due to the dry conditions. Early weaning can be a good management tool to help reduce feed requirements and try maintain ewe body condition.
A ewe's peak milk production occurs after about 2-3 weeks and if not enough quality feed is provided this can drop off quite significantly after about 8-10 weeks. In these situations, the lambs are no longer getting much nutrition from the ewes milk and the two classes begin competing with each other, to the detriment of both lamb growth rates and ewe body condition.
Studies done at Massey University found that lambs weaned above 20kg liveweight coped better with early weaning (but could go down to a 16kg minimum) provided enough suitable feed was available to them.
Suitable feed means a legume dominant pasture. This could be ryegrass/white clover so long as clover content is 30%+ and covers above 1200kgDM/ha, but ideally a legume based crop (such as a clover/plantain mix) between 7-10cm high.
They found that lambs weaned early onto these pastures grew as fast, if not faster than lambs left on mum who were grazing pastures below 1200kgDM/ha (about 4cm).
Clearly if the ewes are on unrestricted feeding of good quality ryegrass/white clover (not grazing below 1200kgDM/ha or about 4cm) then lactation is maximised and therefore lamb growth rates are too. In these situations, it is best to leave lambs on the ewe, unless strategic early weaning is a part of your normal management.
Early weaning onto these types of forages can not only maintain good growth rates in the lambs but also provide a huge benefit to the ewe as well.
It allows more time for condition to be put back on before mating, this could be particularly useful in mated hoggets as they are typically lambed/weaned later. Or for example, old ewes weaned early could be sold immediately freeing up feed for other stock classes.
Anything that can be done to grow lambs fast and/or get them off farm as early as possible will have whole farm system benefits and should be a priority, particularly if the summer is looking to be dry.