Lambs are usually weaned at 12-14 weeks of age, but it is the ewe's body condition score (BCS) and the availability of land that drives the decision when to wean.
Once a lamb reaches the age of 8 weeks, the intake from grass provides more energy than the intake of milk so at 8 weeks old the competition for grass increases. Grass growth and management will impact when the competition happens each year.
If the ewes are in good condition and there is surplus grass then weaning can be delayed without having a negative effect on lamb growth rates.
If creep feed is available to lambs when they are young the daily liveweight gain (DLWG) may not drop after 8 weeks of age, therefore, the weaning decision will be made based on the ewe's BCS and how long before the lambs will be finished.
Where to put the lambs...
Ideally, at weaning, move the ewes and leave the lambs in the same place for 48-72 hours. Once the lambs are over the stress of weaning, they should be moved to a low parasite burden pasture or a forage crop.
Growth rates post weaning...
To achieve optimum growth rates after weaning, lambs should be turned onto grass with a sward height of 6-8cm if set stocked.
On a rotational grazing system, the sward height should be 10-12cm pre grazing and 5-7cm when exiting the pasture. The quality of the grass should be young and leafy which has a ME value of 11.5MJ rather than stem and dead matter (8MJ), however, this is a challenge when grazing aftermaths because they can take 3 weeks to recover.
Nutritional requirements...
A lamb's energy requirements depend on the weight and growth rate.
Lamb Weight (kg) | DLWG (g/day) | ME requirement (MJ/day) |
|---|---|---|
150 | 6.8 | |
20kg | 200 | 8.3 |
250 | 10.0 | |
150 | 9.0 | |
30kg | 200 | 10.8 |
250 | 13.0 | |
150 | 11.1 | |
40kg | 200 | 13.4 |
250 | 16.0 |
Lambs consume 4% of their body weight so a 30kg lamb would consume 1.2kg DM.
If the forage is 11.5MJ, the lamb will consume 13.8MJ/day and should gain 250g per day.
Grazing forage crops...
If lambs experience forages, such as red clover, chicory cereals, with their mothers then they will perform better on these crops after weaning. A transition period is advised and consideration that is takes 3 weeks for the rumen to adapt to a new feed.
Key necessities when grazing forage crops to ensure good utilisation of block or strip grazing:
Run back
Fresh water
Effective fibre source - e.g. Hay
Health Issues...
Weaning time is very stressful to lambs so routine vaccinations and wormers should be given before or after weaning, because stress can affect the immune response, particularly for vaccines, and make lambs more susceptible to disease.
Parasites
Avoid lambs grazing pastures which sheep have grazed on this season already as this can increase the risk of parasite challenge resulting in a lower growth rate.
The main parasites of concern are gut worms which have a major effect on lamb performance. Faecal egg counts should be performed regularly to help to monitor the worm burden, especially if only high-risk fields are available. If the faecal egg count result is high, use an effective wormer and dose to the correct weight. (Discuss with your vet and consult your flock health plan.)
Vaccinations
Vaccination against clostridial diseases and Pasteurella should be done before weaning. If the lambs have not been vaccinated earlier in life, then give the first vaccine 2 weeks before weaning and give the second vaccine 4 weeks later. (Discuss with your vet.)
Trace Mineral Deficiencies
After weaning lambs some farms can struggle with poor lamb growth weights and losses. This can be related to cobalt deficiency, or 'pine' and can sometimes be easily solved or sometimes is complicated by other underlying issues.
A heavy worm burden can exacerbate the issue. Treatment options include bolus, drench or in feed mineral supplementation. Best responses are seen if supplementation is primed approximately 4 weeks before weaning. Long-acting injections of vitamin B12 can help to support through the weaning period.
Selenium deficiency can also be seen in lambs and shows itself as stiff lambs, or sometimes as heart issues. Again, supplementation can be by bolus, drench or in feed mineral. Supplementing ewes prior to lambing can also support the lamb through milk and colostrum.
Farm status can be established by using grass and forage samples as well as blood samples of cohorts of lambs and ewes. Use careful interpretation of the results and discuss with your feed representative and vet.
Lamb Products
Progressive Rumistart Pellet 18%
High-specification starter pellet formulated for lambs starting at 3 days old.
Incorporates sugar beet to ensure optimal feeding through Advantage Feeders.
Contains starch and sugar to promote rumen development and quality protein sources, such as soya, to aid in frame growth.
Fully mineralised, including Nustart, to support rumen development and overall animal health.
Enriched with Safmannan to support intestinal health, development, and the immune system.
Also includes Ammonium Chloride to reduce the risk of urinary crystals in male lambs.
iStart Pellet 17%
Fully mineralised starter pellet suitable for all calves and lambs from 3 days old.
Contains starch and sugar sources to promote rumen development and protein sources to support growth.
Includes Nustart to support rumen development and animal health.
Also enriched with Safmannan to support intestinal health, development, and the immune system.
Contains Ammonium Chloride to reduce the risk of urinary crystals in male lambs.
Lamb Grower Pellet 17%
Fully mineralised pellet suitable for lambs and calves from 3 days old.
Contains various starch and sugar sources to promote efficient growth.
Includes Ammonium Chloride to reduce the risk of urinary crystals in male lambs.
Intensive Lamb Nut 16%
Fully mineralised nut ideal for growing lambs.
Contains good levels of various starch and sugar sources to promote efficient growth.
Includes ammonium chloride to reduce the risk of urinary crystals in male lambs.
Supports finishing when lambs are on good grass or with ewes.
Super Lamb Nut 15%
Fully mineralised nut with high levels of various starch and sugar sources to promote efficient finishing.
Includes Ammonium Chloride to reduce the risk of urinary crystals in male lambs.
Supports a faster finishing process.
Alka Finisher Nut 15%
Fully mineralised finishing nut suitable for feeding to cattle and lambs from 10 weeks old.
Contains no supplemental copper and includes essential lamb minerals.
Ideal for finishing cattle and lambs
Contains 15% alkagrain to provide higher levels of starch and sugars without risking rumen acidity.
Includes ammonium chloride to reduce the risk of urinary crystals in male lambs.
DN Coarse Mix 16%
Palatable coarse mix designed for calves, lambs, and tups.
Contains ammonium chloride to reduce the risk of urinary crystals in male lambs.
Includes Nustart to support rumen and intestinal development and health, as well as Actisaf yeast to promote rumen health.
To read the full tech guide on Lamb Nutrition click the link below...
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