Options for finishing lambs on Irish Sheep Farms

Michael Gottstein discusses the challenges sheep farmers face due to difficult weather, impacting lamb performance, grass growth, and the need for strategic lamb drafting and sales to ensure sufficient resources for ewes.

It has been an unusual and difficult year for sheep farmers. The difficult spring weather resulted in most farms seeing lamb performance being hit and it is likely that on many farms lamb weaning weight will be back across the board. In addition to a reduction in animal performance grass growth has also been challenging on most farms.

Depending on stocking rate, grass growth rate and the quantity of fodder available on the farm it is prudent to put in place a plan for lamb drafting / sales. In years where lamb performance is compromised the biggest challenge is to get lambs off the farm in a manner that ensures there is sufficient grass available for the ewe flock. There is little point in feeding lambs into the back end of the year on grass that will be required to maintain the ewes. It is simply robbing Peter to pay Paul.

Asses weight categories of lambs

Weigh lambs and identify what proportion of the lambs fall into the various weight categories.

Less than 25kg

These are very light lambs that will not be finished in this calendar year. Feeding high levels of concentrates to this cohort of lambs is likely to be uneconomical. The best option for these lambs is to allow them to grow on grass/forage until they reach 35kg. Once over 35kg these lambs can be placed onto concentrate based diets and finished economically.

25 – 30kg

These are light lambs that again need to be given a chance to grow before being put on a finishing diet that contains significant levels of concentrates. Depending on forage availability on farm these lambs are also a cohort that could be considered for selling as store lambs as they are still long keep lambs.

30 – 35kg

This cohort of lambs are the faster growing and better performing lambs on the farm. All going well the last of these lambs should be drafted by the end of October. This group will be feeding lambs into the finishing group as the lambs exceed 35kg liveweight.

35kg+

This is the finishing group. Lambs in this group represent the fasted growing lambs on the farm. With good grass, a focus on flock health and some concentrate supplementation these lambs should finish quickly (1.5kg – 2kg liveweight gain per week). Optimum supplementation rates for this cohort of lambs is between 500 and 750grams per day depending on grass supply and quality.

By targeting concentrates at the finishing lambs it reduces the amount of meal being fed when compared to feeding all the lambs. The finishing group allows for consistent lamb drafting and as lambs in the lower groups increase in weight they can be moved up into the finishing groups.

It is also important to keep on top of health issues. Lameness, parasites and mineral deficiencies (in particular cobalt) can have a significant impact on lamb performance. There is little point in feeding expensive concentrate feed to lambs that are lame, mineral deficient or have a belly full of worms.