Finishing Store Lambs on All-Concentrate Diets

Frank Campion, Noel Claffey, & Michael Diskin, Teagasc, investigate the potential for finishing hill lambs on all concentrate diets. They advise careful management and performance monitoring to maximise the return from these lambs.

Often on sheep farms lighter lambs left over at the end of the year require a period of meal or concentrate feeding to finish these lambs. This is most typically seen in hill bred store lambs which are often purchased by finishers with the aim of finishing these lambs on an all concentrate diet. The steps required to effectively do this are outlined below:

Step 1: Maximise animal performance through good husbandry

While finishing lambs indoors can be a profitable enterprise where lamb purchase price is favourable it is important that lambs are slaughtered on time and in the correct specification to maximise the returns. Table 1 shows the suggested minimal drafting weights for male lambs finished on an all-concentrate diet. Once lambs are eating ad-lib they should be weighed regularly and drafted for slaughter. It is important that lambs are also handled prior to slaughter to ensure there is adequate muscle and fat cover for slaughter. It is also crucially important that there is good animal husbandry throughout and mortality rates are kept to minimum. Purchased lambs need to go through a full bio-security programme upon arrival on the farm including worm drenching, fluke drenching and vaccination for clostridial disease,  pastuerella pneumonia and where necessary Orf.

Step 2: Feed Management

It may be necessary to train lambs to eat concentrates 2-3 weeks prior to housing – outdoor with creep feeders or indoors with access to roughage. Where finishing lambs on an all concentrate diet, ensure diet is formulated for this purpose, initially offer 300 g/lamb/day and increase by 200 g/lamb/day every 3 days until full feeding level is achieved, and continue to offer a small quality of long roughage (hay, silage, or straw).  Once full feeding is achieved ensure the lambs have access to concentrates at all times. Ensure that lambs have water at all times.

Concentrates should be carefully formulated using high energy ingredients; Table 2 highlights the energy density of various ingredients that can be found in lamb finishing diets. It is vital that when finishing males lambs ammonium chloride is included in the concentrate at a rate of 0.5% to prevent urinary calculi. A small proportion (<2%) of hill lambs may refuse to eat or be very shy feeders. Usually they stand at the rear of the pen when meal is fed and get progressively thinner with time. It’s best to remove them and put them on pasture. Good stockmanship is vital as is avoiding overcrowding and having large numbers of lambs in a single pen.

Step 3: Housing Management

As with all livestock, ensuring that the sheep house is well ventilated and adequately bedded, where using straw-bedded sheds is a vital component of managing store lambs on all-concentrate diets. Also ensure that there is adequate trough space for lambs – especially during the time that they are being built up to ad-lib concentrates. (need 30cm per lamb of trough space). If lambs cannot eat together when building up to ad-lib concentrates then some lambs may not consume any concentrates while some will potentially over eat and develop acidosis.

Shearing lambs will help keep them cleaner, particularly on slats but research carried out in Teagasc Athenry has shown there is no performance benefit to shearing lambs being fed indoors on ad-lib concentrates. Shorn lambs take up less pen space allowing 10% more lambs to be put in each pen and as with shearing when lambs are outdoors  it will help to keep them clean. Also, lambs that are being housed for indoor finishing, particularly hill bred lambs, will need to be crutched and the bellies shorn if they are not already shorn. Therefore, the cost of crutching and belly shearing may not be dissimilar to the cost of shearing. If lambs are dirty at point of slaughter they still may need to be clipped at this point to comply with CLP regulations.

Conclusion

Where finishing lambs indoors on an all concentrate diet good husbandry is essential and must be combined with regular performance monitoring to ensure lambs are marketed correctly and at the right time to capitalize on returns available. A crucial aspect of this husbandry is to ensure the concentrate used is appropriate and is managed correctly to prevent any dietary upsets in lambs and to maximise lamb performance.