The causes, management, and production effects of lameness in sheep was one of the topics discussed at the Teagasc National Sheep Conference in Co. Galway.

At the event, held in Ballinasloe on June 18, attendees heard how Teagasc researchers had carried out two trials to determine the scale of the challenge and the best approaches to tackling lameness.

Trial one looked at a national survey of infectious lameness management and flock prevalence, as well as treatment used and lesion recognition.

Trial two was a production impact study carried out on eight BETTER (Business, Environment and Technology through Training Extension and Research) farms around Ireland.

Researchers looked at lameness types and ewe and lamb data to determine if there was any significant correlation.

Infectious lameness

Trial one found that of the 400 farmers surveyed, the national prevalence is 6%, with scald being the highest burden reported.

Significantly, 49% of farmers reported contagious ovine digital dermatitis (CODD).

Teagasc advised farmers that scald is a bacterial infection that relies on entry to sheep via micro abrasions (small cuts), causing red, inflamed skin, and white discharge.

It spreads rapidly and can cause severe lameness, infecting all feet in lambs. Approximately 95% of farms affected by lameness reported scald.

Footrot was reported on 90% of farms surveyed. It is another bacterial infection, that can be identified by a white/yellow discharge, foul smelling, and 'cheesy' sole.

Footrot is often preceded by or present with scald.

CODD is another serious challenge, according to Teagasc, and can often be wrongly identified as severe footrot.

On infected animals, the hoof capsule appears ‘pushed off’ from top (coronary band) down. The infection progresses to the hoof capsule becoming loose or eventually detaching.

Farmers are advised that foot bathing is ineffective for treating CODD.

Production impact

The trials found a high variability between farms experiencing a negative body condition score (BCS) impact from lameness events, with higher lameness trending towards greater negative impacts.

Both mating and mid-pregnancy BCS were negatively effected by lameness. Nearly 22% of lame ewes reported a BCS of less than 3 at mating, compared to 15% of non-lame ewes.

During mid-pregnancy, lame ewes with a BCS of less than 3 rose to 26% compared to 19% in non-lame sheep.

Teagasc research calculates that lame lambs can see reduced growth rates by as much as 10g/day or up to 1kg at weaning.

Where margins are tight, this can cause a critical reduction in profitability.

Mitigation

Foot bathing is very effective in combatting lameness if carried out correctly, according to Teagasc.

Ensuring standing time is crucial. Foot bathing can be coupled with antibiotics to optimise cure rates and recovery time.

Over-trimming is often an unconsidered promoter of lameness, Teagasc advisers warned.

Approximately 53% of survey respondents reported trimming hooves of footrot-diseased sheep.

However, routine trimming can lead to increased recovery time, increased prevalence, secondary infection risk, and disease spread.

Studies estimate that the cure rate for footrot using antibiotic injections and sprays is around 70%.

This decreases to approximately 10% when foot trimming combined with antibiotic sprays are used.

Timing is crucial, the advisers stressed, stating that there is a significant likelihood for increased lameness prevalence when treatment is delayed by one week or more.

Isolation or quarantine offers the best approach to prevention.

Nearly half of flocks reported buying in breeding females, but one in five did not isolate.

According to Teagasc, prevention is the best cure, especially for diseases such as CODD that can become prevalent within flocks rapidly.

For more information or advice, farmers should contact their local vet practices or regional Teagasc advisers.