Dismal weather conditions have created challenges for farmers finishing their lambs which in turn has led to some factories reporting poorer condition of lambs in recent weeks.
One of the key issues around achieving target weights for lambs has arisen because of the later cuts of silage, which has left less aftergrass available for growth.
The dry matter in grass has been low in recent weeks, causing lamb performance to drop, as their intake has been lower, which in turn has impacted on their drafting.
Ciaran Lynch, a Teagasc sheep specialist, said these challenging factors have been “reflected in the national kill”, which is significantly lower than the same time last year.
As more lighter lambs are being carried into the autumn, Lynch said the remaining lambs should be assessed to see what stage of finishing they are close to.
By weighing a variety of lambs, farmers can estimate how many of the remaining lambs fall in to the following categories for finishing:
- Short term (over 40kg);
- Medium term (35-40kg);
- Longer term lambs (less than 35kg).
Farmers have also been advised to review drafting patterns of the previous years compared to the current season as this will give a good indication of this year’s performance and also what the farm can carry into the autumn.
Achieving target weights
To deal with additional numbers of lambs, farmers must ensure there is sufficient grass for the coming weeks by applying fertiliser when conditions allow.
“Better responses will be achieved with August applications rather than waiting for closer to the fertiliser deadline,” Lynch added.
Post-weaning, lambs will typically achieve growth rates from 200g/day declining to 150g/day, or 1.5kg to 1kg gain per week from July through to early September.
However, to date, and perhaps unsurprisingly given the recent weather conditions, these growth rates are not being met.
Farmers will have to introduce a level of concentrates to the diet of the lambs they are finishing, often splitting the lambs into groups of similar weights, ideally within 5-10kg of the required drafting weight.
Using troughs for feeding lambs is a less costly method than using creep feeders, and it will allow all lambs access to the same level of feed at once.
Feed rates of up to 0.5kg in a single feed will deliver improved performance with good efficiency.
In circumstances where bringing lambs to target weights has been slow, Lynch recommends increasing the feed rates to 1kg, split into twice daily feeds to a finishing group.
For some farms, Lynch said selling a portion of stores may be an “advisable option” to reduce the demand for feed and provide a welcome income stream.
Drafting lambs
The number of lighter, under-fleshed lambs brought to factories is posing challenges for processors to market them, and is not returning the maximum profit to farmers that supplied the lambs.
Lynch suggested that such lambs “may have been better suited to the live trade or [to receive] further feeding”.
Taking into account that, when drafting lambs, kill-out will decline as the season progresses; lambs born in March are now between 20-24 weeks old.
Typically these lambs should have an average kill out of 42-43% at this time of year.
To achieve a 20kg carcass, Lynch recommends that lambs would need to be drafted at 47.5kg with adequate cover.
“Other factors such as breed, gender, and level of feed will influence lamb kill out and need to be considered when drafting lambs,” Lynch added.