Top tips for weaning lambs

Preparing lambs for weaning is extremely important to ensure they do not go backwards in terms of growth and health once milk feeding is suddenly removed.

Top tips for weaning lambs:

• Ensure lambs have ad-lib access to clean fresh water and palatable creep feed
• Remember that weaning can be a stressful time for lambs – minimise changes e.g keep the lambs in the same pen before and after weaning, keeping their groups the same 
• It is recommended to abruptly wean lambs when they reach day 30 – 40 or weigh 16kg. 
• Monitor creep feed intakes before weaning – Wean when lambs are eating 200gm day for 3 days of 18%-20% CP ration

Milk replacer of course will be the lambs main feed source for the first few weeks; however, they should be provided with fresh creep, clean water and forage such as straw to nibble on from the first week of life. Although they may not consume very much, it should be available to them so they are familiar with it from early on and younger lambs will learn from their older pen mates.

Weaning is a very stressful time for lambs and often there can be several barriers that get in the way of successful finishing that rearers should be aware of and avoid these pitfalls where possible.

The weaning process should be as stress free as possible and limits should be put on the number of changes taking place around this period. Stress can have a negative impact on the lambs’ immune system leaving them less robust to fight disease at this point. 

Wean when lambs are eating 200gm day for 3 days of 18%-20% CP ration

To minimize problems from stress and digestive upset, lambs should be weaned abruptly by removing the source of milk replacer from the pen. For the first 7 to 10 days after abrupt weaning, lambs undergo a growth check (weight loss) as a result of lower feed intake. Consequently, lambs may appear gaunt and exhibit a rough wool coat before full adjustment to dry feed.

Lambs can be weaned as early as 15 to 20 days of age, but weight is the most important factor to consider before weaning. To minimize growth check and to ensure their ability to consume dry feed, lambs should weigh a minimum of 16kg. 

Lambs undergo less stress at weaning when they are weaned as a group and left in the same pen with the same feed they were receiving before weaning. Lambs should continue to receive a feed containing 18 to 20% crude protein until they reach a minimum body weight of 20kg. Thereafter, lambs can be switched to a lower protein growing diet or be placed on high quality pasture for grazing.

Coccidiosis is most common in weanling lambs. Enterotoxemia (overeating disease type D) is more common in early weaned lambs. It can be prevented with vaccination. It presents itself as diarrhoea containing mucus/blood and often lambs appear dull and lose weight rapidly causing prolonged gut damage. It is a costly disease as it effects lamb health and performance. Oocysts can often remain in the environment from previous years or ewes shed oocysts on to pasture or bedding when housed.

A discussion with your vet regarding  vaccination against Clostridium perfringens types C & D at three to four weeks of age and boostered three weeks later should be had. 

Stress is a greater consideration when practicing early weaning – not natural by tradition but with attention to detail it can be minimised for lambs

– stepwise weaning by volume but very labour intensive

– lowering amount of time on the feeder increases risk of gorging and subsequently bloat

– abrupt weaning can be stressful and should only be carried out on healthy thriving concentrate eating lambs; minimises the risk of bloat. One way that has anecdotally minimised stress is abruptly weaning but leaving the teats in the pens with the lambs to allow sucking behaviour.

Quite often pet lambs reared on shine ewe-reka ad-libitum can outperform their siblings which are fed on the ewe. There are several reasons why ewes can drop in their milk supply such as diseases presenting e.g., Johnes or perhaps they get burdened by parasites or lameness and the list goes on.

Monitoring lamb performance through weighing and investigating any lambs that aren’t meeting their targets is essential to spot a problem early. Lambs at around 8 weeks old should have an average daily live weight gain of >250g per day. For example, a birthweight of 3kg for triplet lamb selected to be artificially reared gaining 250g/day – assuming the lambs are killed at 21kg deadweight (at a kill out percentage of 50%) will take 156 days to finish and reach their target weight. However, some lambs fed ad-lib have the potential to achieve >400g/head per day which would speed up the finishing process and post weaning can be intensively fed indoors on concentrates and forage.

Recent trial work (Claffey et al., 2018) showed lambs fed ad – lib concentrate diets versus lambs fed 50% concentrate: 50% forage, or forage ad libitum had greater average daily liveweight gain, feed conversion rates and higher carcass weight.  Therefore, ad-lib concentrate feeding has its advantages when aiming to finish the lambs early and achieve the best price.

Urinary calculi is something to be mindful of in male lambs. It can occur when stones (which are usually made up of phosphate salts) block the urinary tract and prevent urination. It is important to ensure the feeding ration contains a calcium to phosphorus ratio of at least 2:1. Avoid inclusion of additional magnesium or phosphorus to the concentrate diet. Ammonium chloride (0.5%) can be added to help acidify the urine and prevent the formation of calculi. Roughage will also aid with salivation and rumination which will increase the amount of phosphate excreted in the urine.

Hygiene should be top notch and cleaning out water troughs regularly is important. History of previous year problems should be highlighted and avoided where possible. In addition, where possible younger lambs should not be grazed behind older lambs and stocking density should be well managed to avoid poaching and tight grazing.

Mineral deficiencies can also cause pitfalls in getting the lamb to where it needs to be on time. Cobalt, selenium and copper are three important minerals to ensure the lamb is thriving well and reaching their targets. Healthy lambs grow quicker and it is vital to optimise the health of lambs where possible. If weight gain is an issue and everything else appears to be in line it may be a good idea to obtain blood samples from the lambs to identify if they are lacking in a specific mineral or vitamin. CCN (cerebrocortical necrosis) is a severe brain condition in lambs post weaning and is often caused by changing their ration. The cause of CCN is a lack of Vitamin B1, this vitamin is produced by rumen microbes. There are different things which can alter the balance of rumen microbes such as severe changes in their diet and as a result the amount of vitamin B1 produced decreases and thus leads to CCN. To prevent this, it is necessary to make sure diet changes are very gradual to ensure a smooth transition.

In summary, we know that lambs are very vulnerable during weaning as it is stressful time for them (changing diet and perhaps their environment and pen mates) so avoiding stress by minimising as many changes where possible around this time allowing for a gradual transition will make it a lot easier for them to progress in their performance and health post weaning as opposed to going backwards and experiencing a growth check. Monitoring, measuring and managing the lambs correctly is vitally important to achieve successful finishing of lambs on time by helping them to meet their targets.