21 March 1997


COWS that are prone to lameness or difficult to trim because the bone in the outer claw is set low should not be used to breed heifer replacements.

And herdsman Anthony Renwick explains that with some cows it is difficult to trim the claws level without trimming into softer horn near the bone. He adds that this trait seems to occur in some cow families in the 160-cow herd at New Buildings Farm, Stafford.

Dr Murray agrees and some animals, he says, are indeed more susceptible to lameness than others. "With good records you can identify high risk cows to avoid breeding from them – reducing lameness in the longer term.

"It is expensive to spend £600-£700 rearing a heifer that will need to be treated for lameness and which may only last one or two lactations," he adds.

When high risk cows are identified in the herd, such as one that had foot ulcers every seven months, it is possible to lower the risk of clinical lameness.

Some cows may also have faster horn growth. "In this cow it is taking seven months for the corrective trimming benefits to disappear and the same risk is back again," says Dr Murray. When horn grows faster than it wears, it would be worth trimming her feet twice a year. In general however, Dr Murray advises annual trimming at drying off.