Sheep producers face (or faced) another difficult choice this season; continue to feed their ewes during lambing, risking mismothering or stop feeding, risking the health and performance of their ewes and lambs. Substantial research has been conducted into reducing lamb mortality. It shows the importance of the early bond between ewe and lamb. Ideally a ewe will stand and groom her lamb(s) immediately after delivery, will help the lamb to nurse and will spend over four hours with the lamb at the birth site. This process cements that bond. If it is disrupted, such as when the ewe bolts to the feed trail or heads for the self-feeder, mismothering can occur leaving the lamb vulnerable to starvation, exposure and predation.
However, we all know the consequences of underfeeding; pregnancy toxaemia before lambing and reduced lactation and poor mothering after lambing. Some sheep producers have received sufficient rain to enable them lamb on saved pasture without feeding. Unfortunately, others have no choice but to feed during lambing. What strategies can they use to avoid mismothering?
The first is to manage twin bearing ewes separately from single bearing ewes, in smaller mobs. Dr Gordon Refshauge, based at the Cowra Research Station, recommends that twin bearing ewes should be lambed in small mobs but says there is ‘no magic number’ on the number of twin bearing ewes per mob. He also found no difference in lamb mortality at stocking rates between six and eight ewes per hectare.
Gordon commented that some producers may be able to drift ewes yet to lamb from recently lambed ewes. He also mentioned research conducted by Dr Peter Holst at Cowra showing that feeding ewes in the early afternoon allowed most time for mothering up before nightfall. Phillip Graham, previously a sheep and pastures expert with NSW DPI and now a consultant, considers that self-feeders can be used for lambing ewes provided no more than 220 single ewes or 100 twin bearing ewes have access to each feeder. He commented that trail feeding usually gives better control of the amount being fed and that disturbance can be reduced by feeding two to three times per week rather than daily.
Some sheep producers broadcast albus lupins or faba beans onto paddocks to supply sufficient feed for several weeks, avoiding the need to trail feed. Others plan to use whole cotton seed dumped into the paddock as ewes don’t seem to rush to consume it. Finally, as Phil Graham noted, under these tough and stressful conditions, graziers need to avoid being tough on themselves if lambing is less successful than in more benign years.