15 December 1995

Slurry+feet = high dermatitis

SPRAYS and formalin foot-bathing fail to help control digital dermatitis in dairy cows, said Dr Murray.

"When you have a high incidence of digital dermatitis you have too much slurry in contact with the feet.

"Young cattle are susceptible in badly designed yards or cubicles that rely on mechanical cleaning methods. The effects of poor housing are made worse by the spread of bacteria from cow to cow. So it is vital to reconsider ways to keep cows feet free from slurry."

Bacteria causing digital dermatitis could be brought on to the farm by infected stock or dirty boots. These bugs then multiplied and spread from cow to cow in slurry. The damage is made worse when cows stand in water, for this undermines their natural defences.

Dr Murray advises treatment using two foot-baths where the first contains clean water. This is in preference to using one footbath and sprays, which are "ineffective and fail to contribute to controlling the infection".

Most cows will dung in the first footbath then go though the treatment bath more easily. "Solution concentration alters by less than 2% when using this method with a 350-litre bath for 350 cow passages. Without the pre-bath, dung destroys the solution strength."

He also recommended the minimal solution design of footbath. This has a foam mattress covered in rubber to reduce the solution needed by 60%. But he said it still gave effective bathing, as each foot depressed the foam and the hollow filled with water. But to be effective the bath must be kept clean.

Both copper sulphate and oxytetracycline footbaths showed substantial improvement in locomotion scores for four to five weeks after treatment, he said. &#42