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 but by eight weeks of age pasture overtakes milk as the major part of the diet of a lamb. Milk contributes only about 10% of nutrients for the lamb and 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.
- Lambs should be marked, vaccinated. If they have been recently mulesed, allow four weeks to recover before weaning to avoid setback.
- ‘Train’ lambs 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).
Some benefits of early weaning
- Feed cost savings – the requirements of a ewe with a lamb is higher, about 3 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 establish and grow ahead of the grazing stock.
- Worms – lambs have a lower worm burden, as worm control can be provided earlier and they will not be grazing the pasture being contaminated by their mothers for as long.
Management of early weaned lambs
Weaners are your replacements in the breeding flock. What happens to your weaners now will affect their lifetime liveweight, wool production and their future reproductive capacity. It is important to optimise conditions for your growing weaners. To optimise future production from weaners, aim for 30kg minimum liveweight before summer and a condition score of 2.
Vaccinate at weaning for the main clostridial diseases, pulpy kidney, tetanus and cheesy gland. It is essential to provide this booster vaccine at weaning as the dose given at lamb marking will not 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. Vaccinate behind the ear.
Provide high energy and high protein feed to ensure the lambs keep growing. Weaned lambs require about 11 megajoules (MJ) of energy and 14-18% crude protein 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 to the lambs while still on their mothers to 'train' the lambs to consume the ration and allow the rumen to adapt to the feed type. Weaners should be fed a minimum of two to three times per week. Initial feeding rates could be 100 grams (g) per head/day and altered to achieve growth in the weaners. Weaners will benefit from grazing green feed for as long as possible this spring. A paddock with a FOO of 800-1000kg/ha will be sufficient to provide growth. (This equates to 80% green cover at one centimetre or 50% cover at 3-4 centimetres). Where insufficient pasture is available, continue to provide a lupin supplement in the paddock.
Monitor your weaners
Weighing a group of 50 weaners from the mob every two weeks will give a good indication if the feeding rate is adequate. Weaners should be gaining at least 30g/head/day and up to a potential of 200g/head/day until the start of summer. Weighing lambs at weaning and calculating the required daily body weight gain to reach 25kg by the end of November will help to determine whether your feeding program will be sufficient to optimise weaner survival over summer. Lambs have a greater potential to gain weight when they are younger so it is better to grow them as soon after weaning as possible, than try to gain weight later when stubbles or this year's harvest is available.
Feed types for weaners
Cereal grains can be used as part of the supplement if lupins are in short supply. To meet the protein requirement for growth at least one third of the ration should be lupins. Remember to introduce cereal grains gradually to all sheep to reduce the risk of acidosis. This can be achieved by increasing grain supplements in small increments of about 50g every two days over 14-21 days. Gradual introduction to different types of grains is also recommended (for example oats to barley or wheat). Use the highest quality roughage (pasture or hay) available during introduction of grains, if possible.
There are also some very good quality commercial pellets now available for weaners. Choose pellets with more than 12MJ of energy per kilogram of dry matter and more than 15% crude protein for weaners to ensure their requirements for growth can be met.
Spring pasture growth should provide sufficient energy and protein for the weaners. Be aware that quality of pastures declines rapidly after flowering and continues to decline as the pastures 'hay off'. After the pastures have dried, the quality is usually too low for weaner growth and they will need supplements to maintain growth. From wilting, start to feed weaners 50g/head/day of lupins to continue a gradual increase in liveweight. Continue to monitor a group of weaners for body weight gain.
Parasites can seriously reduce weaner growth rates and survival during the spring and summer months. Weaners should be treated for worms at weaning time, using an effective drench, before turning the newly weaned lambs onto a 'low worm' pasture. Worm egg counts after pasture senescence will determine if you need to drench your weaners again in summer.
Weaners also require a cool, clean water supply, especially as the pastures dry out and the hot summer months arrive. Salt levels in water must be below 6000 parts per million (ppm), or 1100 milliSiemens per metre (mS/m) for weaners to drink. Lot fed or confinement fed weaners require better quality water, up to 900mS/m. Poor quality water will reduce water intake; this reduces feed intake and growth.
Creep feeding of lambs provides an alternative to early weaning during difficult seasons and is especially important when the lambs are too young or weak to early-wean from their mothers. This method of ewe and lamb management provides less flexibility for ewe management, but may be necessary when the ewes are in poor condition during lactation and/or the lambs are too young or weak to wean off their mothers at an early age.
Creep feeding involves the provision of high energy and high protein feed supplements to the lambs while they are still with their mothers. There are several quality commercial milk pellets on the market to suit these young lambs. Creep feeders consist of enclosures that are constructed to allow the lambs to access the high quality feed, while denying access to their mothers. The enclosures have vertical bars at spacings to allow access for the lambs but at spacings that are too narrow for the ewes. Further security for the feed can be provided by placing a horizontal bar at a height taller than the lambs, but smaller than the height of the ewes. An example of a creep feeder is shown below.
The front panel of the creep feeder can be constructed of welded steel bars, while spare gates or sheep yard panels can be used for the rear and sides. It is best to provide the creep feed in troughs within the enclosure to reduce the risk of health problems for the lambs.
Creep feeding has varied success. One problem is that sometimes it takes time for the lambs to find the feed.
Tips for creep feeding
- 'Training' the lambs to accept the feed is hastened by feeding some of the pellets initially in a trail with their mothers. The lambs will learn to recognise the pellets as a feed source much earlier if their mothers show them.
- The creep feeder should be placed near the main campsite of the flock (and/or near the trail feed area for the ewes) so the lambs have constant access to the feeder. It is important to continue to supplement the ewes while creep feeding the lambs, as the lambs will still be obtaining some milk from their mothers.
- There may be some risk of soil erosion around the creep feeder, so gravel may need to be applied around the base of the feeder.
- Creep feeding provides an alternative management strategy for feeding small, young or weak lambs and also assists the ewes by reducing the energy demands of the lambs.