Calf ear tags alert farmers to early signs of pneumonia

Using specialist ear tags to alert farmers to increases in calf body temperature has been shown to enable pneumonia to be picked up early, allowing prompt treatment, improved growth and less antibiotics use.

Preliminary findings from a Royal Veterinary College trial using FeverTags found the tags were able to pick up temperature increases before visual signs of pneumonia, said FeverTag’s Tim Farrow at the recent IFA Precision Beef Management Conference.

See also: New ear tag can detect early onset of cattle pneumonia

“As a result, 65% of pyrexia [temperature increase] could be resolved just with the use of non-steroidal anti-inflammatories,” he said. Thirty-five percent required further treatment with antibiotics.

FeverTags use a specialist probe which is inserted into the ear of a calf or cow and automatically records temperature every 15 minutes.

Once body temperature is at 39.7C or above for six hours the tag will flash. Mr Farrow said the tags could alert farmers 24-72 hours before visual signs of illness.

“In the trial, once the tag started flashing, the calf was treated with an anti-inflammatory straight off.

“If the tag was still flashing the following day it was followed up with an antibiotic,” explained Mr Farrow.

The RVC trial took place on a year-round calving 300-cow Holstein Friesian dairy unit in Dorset, which had traditionally struggled with calf pneumonia problems.

Sixty-eight heifer calves were involved in the trial. Calves were paired off, with one given a FeverTag.

All calves were group housed in a shared airspace and monitored for signs of illness using the Wisconsin Calf Score system.

At the same time, improvements in colostrum management, pen layout, ventilation and the use of calf jackets were also made.

The trial found that calves with the tags were also 6kg heavier at eight weeks old than those that didn’t receive them (see table).

“There was also a statistical liveweight gain difference on the calves that had the tags in and those that didn’t and that’s purely down to the fact that you weren’t waiting for the animal to be sick before you treated it,” commented Mr Farrow.

On the trial farm, the tags also picked up that every calf had at least one episode of pyrexia at some point. 

RVC FeverTag trial: Calf performance


With tag

Without tag

Liveweight gain (kg)



8 week liveweight (kg)