Too many UK herds were culling cows at little more than two-and-a-half lactations against a target of six lactations due to acidosis-induced lameness, which costs between £180-£300 a case, reported Irish vet Desmond Rice.

This was largely unnecessary as correct nutrition could redress the balance.

Too much lactic acid in the rumen could attack hoof tissue leading to lameness, Dr Rice warned.

“We forget there can be 750kg resting on four points, each measuring just 8in sq.”

Rumen pH needed to be maintained at 6-6.8. Allowing it to fall led to acidosis and below pH5.5 feed efficiency was affected.

“A healthy cow produces 1kg a day of its own natural buffer (sodium bicarbonate) in the saliva.

When working well this can be seen leaking from a cow’s mouth, but mustn’t be confused with heat stress,” warned Dr Rice.