The current lack of pasture feed may require ewes to be hand-fed prior to and during lambing. Although recent rains in some areas will lead to pasture growth, it is likely that many growers will be feeding during winter.
Prior to, during and after lambing, a ewe’s nutritional requirements change markedly.
During early pregnancy, foetal growth is minimal, hence ewes can be maintained on a diet similar to dry sheep. During this period, they should be maintained at a minimum of two score or above, with three score being ideal. Twin bearing ewes should ideally have a condition score 0.5 higher than singles.
During the final six weeks of pregnancy, significant lamb growth occurs, with the weight of the entire conceptus increasing by approximately 10 kg, with the lamb growing to about 4-5 kg. During the last 6 weeks of pregnancy, overfeeding can lead to rapid lamb growth and birth difficulties. Underfeeding ewes, can lead to reduced mothering instincts and weaker lambs, resulting in increased losses.
During the last month of pregnancy, the feed requirement increases to approximately 1.7 times that of a dry sheep. A diet comprising only 8% crude protein is required, with ewes able to be maintained or supplemented with grain to meet their requirement.
During the first month of lactation, the feed requirement is approximately 2.5 times that of a dry sheep, with the diet required to contain at least 12% crude protein. For adequate milk production, the diet post-lambing should contain at least 20% roughage, in the form of good quality hay. If necessary, higher protein grain such as lupins, may be fed to meet the protein requirement.
During the second and third months of lactation, the feed requirement drops slightly, but the requirement for protein remains.
The following table shows the maintenance requirements for ewes at various stages of pregnancy and lactation. The table assumes that grain is wheat of at least 12% protein and hay is good quality lucerne hay. Where grain has less than 12% protein, an alternative protein source is required. Under current conditions in eastern areas, most pastures will be providing at least part of the required diet and this will reduce the supplementary feeding required. Hay is not required until ewes are lactating.
In times of drought and when handfeeding lambing ewes, mismothering can be a significant cause of lamb death. Reducing the mob size as well as the stocking rate will help reduce this. Feeding ewes daily and in the afternoon, will also reduce mismothering and keep ewes on a constant plane of nutrition.
Maintenance Requirement for Ewes
Skeletal material accounts for a significant percentage of the weight of a developing foetus. Skeleton has a high Calcium content and this requirement for Calcium creates a significant draw on the Calcium stores of the ewe. Lambing ewes obtaining most of their diet from green pasture, generally do not require supplements. However, ewes on a grain-only diet require an additional supply of Calcium and Sodium. The most cost-effective way of providing this is by supplementing with lime and salt.
Sheep (particularly lambs) on grazing cereals, may also benefit from the addition of Magnesium. Adding Causmag to the lime and salt mix, is the most cost effective way to supply Magnesium.