Ralph Behrendt, Senior Technical Specialist – Sheep and Beef Networks
After 2 tough years, many farmers across the state now have good numbers of lambs on the ground approaching weaning time.
Weaning is a routine job on the calendar. But for lambs, it is one of the biggest changes they will face.
Overnight, they move from relying on mum to find feed and guiding their day, to becoming a member of a new flock with a new hierarchy, where they need to find feed and water, and cope with weather, worms and other health challenges.
Most weaning problems can be reduced with good planning, preparation and regular monitoring.
The main aim is to wean lambs at the right weight and age, put them onto the best feed available, and keep a close eye on them during the months after weaning.
A bit of extra attention at this stage can mean more lambs alive, heavier weaners, and better replacement ewe lambs for the future flock.
Before weaning
Helping lambs survive and thrive after weaning starts well before they get drafted out and placed in a paddock without their mothers. Ideally, joining of rams will have been kept to 5 weeks to reduce the spread of age and weight at weaning, limiting the tail of young light lambs.
Achieving optimum ewe condition at joining, pregnancy and lactation improves lamb birthweight, milk supply and lamb growth to weaning. Ensuring feed on offer is not limited during lactation also helps deliver the growth rates needed to wean heavier lambs.
Lambs start grazing from a young age, and by about 8 to 12 weeks, pasture is providing most of their feed intake. For many flocks, weaning around 12 to 14 weeks after the start of lambing is the recommended target, but earlier weaning may need to be considered under tight seasonal conditions to manage light lambs and ewe condition separately.
Conduct imprint feeding of lambs with grain or pellets before weaning, while they are still on the ewe. Offering ewes and lambs as little as 3 small feeds prior to weaning helps lambs recognise the feed post-weaning, which can reduce shy feeding and the longer training time required with inexperienced weaners post-weaning.
Being able to get weaners consuming supplements quickly and at the right amount, as the season turns is critical to avoiding a growth check.
Prepare weaner paddocks with high-quality feed (1,800 – 2,100 kg DM/ha feed on offer), low worm risk, minimal grass seeds, shelter and easy access to clean water. Imprinting lambs to drink from different water sources whilst on the ewe can also help them find and consume from different water sources post-weaning.
Plan flystrike and worm control in advance. Use worm egg counts and an effective drench strategy suitable for the property. It is also worth checking yards, troughs, feeders and fences before the weaning day so the job can be done quietly and with minimal stress.
At weaning
Aim for lambs to be at least 45% of mature standard reference weight at weaning and draft weaners into weight groups to identify the light-weight tail for separate management and tailored nutrition.
Ensure vaccinations for clostridial diseases and cheesy gland are up to date with the required booster given before or at weaning according to product directions.
Drench with an effective drench and consider flystrike preventative treatments. Make sure to record all treatments including withholding periods and export slaughter intervals to meet regulatory and livestock production assurance requirements.
After weaning
Inspect weaners regularly and keep them on the best available feed, adjusting stocking rate or providing supplements to maintain growth to targets. Monitor liveweight every 4 to 6 weeks and compare results with targeted growth rates for sale lambs, replacement ewe lambs or retained wethers.
Target at least 50 g/day or 1.5kg/month as a minimum post-weaning growth rate for good survival. Even small increases in weaning weight and growth rate improve survival. Aim to keep weaners growing without any setbacks as good nutrition is a foundation for healthy and resilient weaners.
Consider the longer-term weight targets for different animal classes and the growth trajectory required to reach them. For self-replacing flocks, aim for ewe weaners to reach about 50% of mature standard reference weight by the autumn break, about 60% by late winter, and 75–80% by joining/pasture senescence.
The autumn and winter blues
Late summer and autumn rainfall events may increase the risk of ryegrass staggers and phalaris staggers with weaners on some pastures.
The changes in season can be a critical time for weaners, as they navigate reduced feed availability and quality in late summer and throughout autumn. Monitoring of feed on offer and timely adjustments to nutrition are important for continuing growth.
After the autumn break, worm burdens can build up quickly and together with low feed on offer in winter, this may limit growth. Monitor worm egg counts regularly and act quickly on light or poor-doing lambs by drafting them off, checking health issues and lifting feed quantity, quality and supplements.
Continue to monitor for worms, coccidiosis, flystrike and other disease issues and maintain vaccination, drenching and animal health programs based on local risk and veterinary or advisor guidance.
Provide shelter and reduce nutritional stress during cold, wet, or hot and dry conditions, taking extra precautions around shearing time.
Keeping up the momentum by having ewe lambs growing steadily so they reach joining targets will ensure they have the best chance of lifetime productivity.
Finally, don’t forget to record your weaning weights, growth rates, deaths and treatments, so that this year’s plan is evaluated, and next year’s weaning plan can be improved.
