Lambs© Tim Scrivener

Sheep farmers are being advised check growth rates at eight weeks of age instead of delaying weighing until weaning.

Nerys Wright, Eblex regional manager says the performance of lambs up to eight weeks is a critical key performance indicator (KPI) and delaying recording weights until weaning will miss the direct effect of the lactating ewe on early lamb growth.

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Advice for weighing

While weighing the lambs, Ms Wright says farmers should also note ewe weight and body condition to assess how much of their body reserves have been used.

Thin ewes may need supplementing feeding post-lambing or triplets might have to be given priority to grazing or creep feed.

“Weighing lambs at eight weeks of age provide a good indication of how well ewes have been lactating.

“Her peak milk yield occurs three to four weeks post-lambing, so meeting the energy and protein requirements of ewes at this point is crucial in influencing the total amount of milk produced.

“Ewes rearing twins will need to produce about 40% more milk than a ewe rearing a single lamb,” says Ms Wright.

Knowing the flock average and individual daily liveweight gain can be used to calculate the benefit of supplementary feeding ewes post-lambing or creep feeding lambs. However, the birthweight must be accounted for in the calculation.

It can also help with target setting and tracking why lambs have not hit target, says Ms Wright.

“The lamb could be a triplet, small at birth or may have had a poor mother. Collecting and analysing this sort of data can provide sufficient information to be able to implement steps to reduce it happening next year.”

“It also might be appropriate to have some intervention plans prepared before lambs are eight weeks of age to ensure smaller lambs are not the ones still left on the farm next year.

“For example, weaning lambs early onto good grazing, introducing creep feeding (if not already doing so) or selling into a light lamb market,” she adds.

Example eight-week weights

Weight*

(kg)

Average growth rate

(g/day)

15

200

21

300

26

400

32

500

*Assuming 4kg birth weight