29 January 1999

Fear of teeth eruptions in lambs is unfounded

By Emma Penny

AFTER last years panic about new teeth regulations in sheep, a study shows that only 0.28% of lambs slaughtered from January to May had erupted permanent incisors.

According to ADASs Neil Pickard, the study showed that far fewer lambs than expected had erupted teeth before slaughter, giving finishers more confidence to keep lambs for longer this year.

"The new regulations introduced last year tied in with SRM regulations. This meant that a lamb with any permanent incisors which had erupted – the only way to tell a sheeps age – couldnt go for export as it was deemed to be more than one-year-old.

"However, there was thought to be a risk that some lambs from as young as eight-months-old may have erupted permanent incisors. With 6.4m lambs – about 40% of the crop – older than eight months at slaughter, and penalties of £1/kg deadweight or cull prices where lambs had permanent teeth, this was obviously a concern."

This led to ADAS and the Meat Hygiene Service carrying out a MAFF-funded study to assess incidence of erupted incisors in abattoirs. Three abattoirs were visited by ADAS on a monthly basis to monitor lambs, while the MHS kept a tally of throughput.

"We looked at the age of lambs with erupted permanent incisors, their genotype, whether they were downland, upland or hill breeds, and spoke to producers to find out what finishing system they were on. We found only 0.5% of the 12,000 lambs examined between January and May had erupted incisors."

While the five month study looked at 12,000 lambs, the three abattoirs involved slaughtered 500,000 lambs in that period – 11% of the UK crop slaughtered during that time. MHS figures showed only 0.28% of lambs slaughtered during that period had permanent teeth.

"In both surveys, we found that there was a greater number of lambs with erupted incisors as the year went on – in both studies 2.7% of lambs examined in May had teeth," he says.

"The overall incidence of 0.28% was much lower than we expected, and we dont think that was influenced greatly by producers looking at lambss mouths before they went for slaughter."

Mr Pickard says if that figure is extrapolated to the 5.25m lambs slaughtered in the UK in the same five-month period, only 14,700 lambs should have teeth erupted. Assuming a penalty of £1/kg dw on an 18kg carcass, the cost to the UK industry would be £265,000.

"Theoretically, that could be reduced by selling lambs before the end of March because only 0.08% of lambs up until that point showed incisors, reducing the number to 3300 and the price penalty to £60,000.

"However, producers could continue fattening lambs into April and May as the numbers with permanent teeth at that stage were still low.

"Consider the likelihood of better returns from late finished lambs compensating for increased risk of erupted incisors before making a decision on when to sell."

But ensure lambs are sold before they are 12-months-old, and check teeth before lambs are sent for slaughter, he advises. "It might be a better idea to retain females with erupted teeth for breeding or to sell them in August to obtain a better price." &#42

SHEEPSTEETH

&#8226 Abattoir survey.

&#8226 January to May slaughterings.

&#8226 Few with permanent incisors.