Top tips for store lamb production

Stephen O’Callaghan, Drystock Advisor, Teagasc Mullingar, provides practical tips for store lamb production, highlighting key considerations like lamb weight, grass availability, health management, and budgeting to optimise lamb finishing and profitability.

The difficult spring and poor grass growth over the summer months have had an impact on lamb performance across the country. As a result many lambs failed to achieve their target weaning weights meaning there is an increase in the number of lighter store lambs still on farms. A lot of sheep farmers are now assessing what they will do with these lighter lambs: should they sell them as stores now or keep them on and finish them. On the purchasing side, farms that run a store lamb finishing enterprise are assessing what they can pay for store lambs while leaving a margin for profit. Finishing store lambs has been a popular practice on farms over the last number of years with the best prices historically achieved between late February and mid-April. There are some key factors to consider before making your decision on what to do with lambs this autumn.

How long are lambs going to be on the farm?

You need to consider the number and weight of lambs kept and how long these will need to remain on the farm. Ideally lambs should be grouped into three weight brackets <30kg, 30-38kg and over 38kg to allow better management. The target carcass weight and finishing date of lambs must then be established to see how much feed is required to bring them to slaughter. The target carcass weight is dependent on the factory (generally 22kgs). However store lambs will not kill out the same as spring lambs and may be as low as 42% which equates to a live weight of 52kgs. Kill out is affected by several factors such as age, gender (ram lambs -2%), diet (meal +2%), fat cover, and breed. Lambs should be weighed regularly and assessed for fat cover to ensure that they are in spec at slaughter. Under good management there is the potential for lambs to gain 1.1kgs/week during August/September, and 0.8kg/week during October/November on a grass only diet. We can use these figures to calculate how long lambs will be on farm for example a 35kg lamb in mid-September should be approximately 45kgs after 11-12 weeks on good grass. Lowland lambs will consume approximately 1.2kg dry matter of grass per day.

Grass Availability

A key consideration when making decisions on store lambs is grass availability on the farm. If store lambs are present; they are going to consume grass which will not be available for ewes or other stock. This may have a negative impact on next year’s lamb crop if ewes are not fed properly and are in poor BCS, it may also have an impact on grass availability for stock next spring. If good quality grass is not available it is advisable to sell store lambs and prioritise grass towards improving the body condition score of ewes and replacements. Where sufficient grass is available target covers of 1500-2000kgs DM/Ha or 8-10cm, and graze these down to approximately 6cm with lambs.

Health

If purchasing lambs it is advisable to purchase from a known source where the health and vaccination protocols are known. Purchased lambs should be given a quarantine dose for fluke/worms on arrival, foot bathed, and housed for 48 hrs. They should be vaccinated against clostridial diseases and pasturella pneumonia. Lambs should remain separated from other sheep on the farm for at least 4 weeks.

Stomach worms and resistance to wormers are a big issue in store lambs, so faecal egg sampling should be used to determine the need to dose. Fluke may be an issue as there has been a lot of wet weather lately. If treating lambs for fluke use a product with actives against immature fluke. Plunge dipping is the best option for the prevention of scab, lice, blowfly and ticks. Lameness is a huge issue in store lambs and has a significant impact on performance, lambs should be foot bathed regularly in copper sulphate solution 10%. Lame lambs should be separated from the rest of the group and treatment repeated until cured. The Cobalt requirement of lambs is 0.5-1mg per head/day so drench lambs every 2 weeks.

Target to keep mortality below 2% for flocks managed outdoors or 4% for those managed indoors.

Indoor Finishing

The minimum weight for starting indoor finishing is 30 kg, but ideally lambs should be 35-38kgs. Lambs should be trained to eat meal before housing and the feeding rate should be built up gradually. Lambs must also have access to a source of long fibre such as silage, hay, or straw. A high level of lamb performance can be obtained on ad lib meal; in the region of 280-350 grams/day. Ram lambs will perform best followed by weathers and ewe lambs. However the high input cost of meal, availability of straw, and housing capacity must also be considered. Shearing lambs may increase feed intake but does not improve weight gain, so actually leads to a decrease in feed efficiency.

Budgeting

It is important to have a plan in place before making any decision, other factors such as cash-flow and credit availability may also come into play. Farmers should do a budget using the Teagasc store lamb calculator. This programme allows you to estimate the cost of finishing store lambs as well as predicting when lambs will be fit for market.  

A store lamb finishing enterprise if managed well has the potential to leave a good margin and give an injection of cash flow during the winter months but is very dependent on the price available when lambs are fit for slaughter. You must remember that big numbers of store lambs mean big profits in good years and big losses in difficult years.

Alternatively you can contact your local Teagasc Advisor to assist you with a store lamb budget