New research has revealed that smart monitoring can detect sub-clinical changes due to bluetongue infection in dairy cows up to nine days before the first clinical signs appear.

The Faculty of Veterinary Medicine at Utrecht University in the Netherlands carried out the research, monitoring cows with SenseHub Dairy from MSD Animal Health.

Bluetongue virus serotype 3 (BTV-3) has been present on Dutch dairy farms since September 2023, affecting both cattle and sheep.

The clinical signs of bluetongue can be severe - ranging from fever and inflammation to reduced milk production - and by the time visible signs appear, the infection has often already spread within the herd.

Early detection is therefore "key to protecting animal welfare and minimising economic impact".

Research

The Utrecht University study, conducted at the faculty’s research farm De Tolakker, closely monitored 47 sheep and 51 dairy cows during a naturally occurring bluetongue outbreak.

Animals were observed through bi-monthly PCR (polymerase chain reaction) testing and daily clinical examinations, while the cows were simultaneously monitored using the Sensehub technology.

Results from the study found that while 45% of cows had already tested PCR positive for bluetongue, none of them initially displayed clinical signs.

However, SenseHub Dairy had notified abnormalities in their rumination behaviour an average of nine days earlier. 

10 out of the 51 cows went on to show visible signs of infection, confirming that behavioural monitoring can indicate the presence of disease before it is clinically apparent.

Herd health

These findings highlight the critical role of behavioural monitoring in herd health management, according to the researchers.

Detecting bluetongue at an early stage gives farmers the opportunity to take preventive action more quickly, working with their vets to implement biosecurity measures and slow virus spread within the herd.

Early intervention ultimately helps protect animal health and farm productivity.

“By identifying changes in cow behaviour before clinical signs appear, SenseHub Dairy gives farmers time to respond earlier and act with confidence,” a spokesperson for MSD Animal Health said.

"This research from Utrecht University shows how smart monitoring supports healthier, more resilient herds - and gives farmers greater freedom in managing disease risks."