The feed requirements of ewes with lambs at foot are generally higher than when ewes and lambs are fed separately.
In a difficult season with reduced feed supplies, it can be more economical to early-wean lambs from their mothers to lower feed costs and ensure that the ewes regain condition before joining.
This practice becomes even more important as the costs of feeds increase. Ewe’s milk provides the main source of nutrition for lambs until about eight weeks of age.
Lambs will sample pasture from about two weeks after birth and by eight weeks of age, pasture overtakes milk as the major portion of their diet with milk contributing around 10 per cent of the nutrients lambs require therefore little nutritional benefit is gained by leaving them with their mothers after this time.
To wean lambs early
- Lambs should be 8-10 weeks of age, minimum of 10 kilograms (kg) liveweight.
- They should be marked and vaccinated. If they have been recently mulesed, allow four weeks to recover before weaning to avoid setback.
- ‘Train’ them to eat grain while still with their mothers (weaners should be well adapted in drought years due to the ewes being supplemented with grain during lactation).
Benefits of early weaning
- Feed cost savings – the requirements of a ewe with a lamb is higher, about three dry sheep equivalents (DSE), than the requirements of a ewe and lamb separately (1.8DSE).
- Flexibility for ewes – ewes can be fed maintenance rations, placed on poorer feed paddocks, sold or agisted.
- Ewes have a longer time to regain condition before next joining – ewes will take a month and a half to regain one condition score on pastures with a Food On Offer (FOO) of 1500 kilograms per hectare (kg/ha). Until the lambs are weaned, ewes will continue to lose weight on this level of feed. Ewes need to be in condition score 3 by joining to achieve optimum lambing percentages.
- Pastures have a better chance to re-establish and grow ahead of grazing stock.
- Worms – lambs have a lower worm burden, as worm control can be provided earlier and they won’t be grazing the pasture being contaminated by their mothers for as long.
Management of early weaned lambs
Weaners are often your replacements in the breeding flock. What happens to your weaners now will affect their lifetime liveweight, wool production and future reproductive performance. It is important to optimise conditions for your growing weaners.
To optimise future production from weaners, aim for crossbred lambs at 30kg liveweight and merino lambs at 20 kg liveweight before summer and attain a condition score of 2. During dry seasonal conditions, lambs under 20kg at weaning and those losing weight post weaning are at increased risk of mortality so its vital to optimise growing conditions for these stock to mitigate this risk.
Vaccinate at weaning for the main clostridial diseases, pulpy kidney, tetanus and cheesy gland; following label directions. It’s essential to provide this booster vaccine at weaning as the dose given at lamb marking won’t be effective without the booster. Pulpy kidney is probably the most threatening disease for a weaner, particularly when they are to be fed high grain supplements or grazed on unharvested crops. Cheesy gland and tetanus are also important.
Provide high energy and high protein feed to ensure lambs keep growing. Weaned lambs require about 11 megajoules (MJ) of energy and 16.5-20 per cent crude protein in the diet for maintenance and growth. This can be provided from high energy and high protein grain supplements or commercial lamb pellets. Lambs that are weaned early and appear weak may grow better on commercial milk replacer pellets until there is sufficient pasture available.
Provide small amounts of the feed (100 g/ewe) at least three times prior to weaning to ‘imprint feed’ the lambs while still on their mothers and train the lambs to consume the ration and allow the rumen to adapt to the new feed type. Closely observe all the lambs are eating the supplement prior to weaning, if not you will need to extend the imprint feeding period, which will depend on current pasture available, milk from the ewe and the type of grain being fed.