In the Netherlands, an analysis by Royal GD shows a link between calf mortality and the status for the diseases and IBR (Infectious Bovine Rhinotracheitis), BVD (Bovine Virus Diarrhoea), Salmonella and Paratuberculosis. In 2021, the mortality of calves during the first days after birth was on average 6.7 percent on farms that had the status free or unsuspected for all four diseases. This was 7.7 percent on farms that had a favourable status for no or only one disease. In Holland the use of antibiotics on dairy farms has in 2021 decreased 2.3 percent to 2.3 day doses per cow. The number of day doses per cow is based on the daily dose, the amount of active substance administered of a particular antibiotic that is active for one day. The average day doses per cow is then calculated by adding up all the daily doses and dividing by the average number of cows present in that particular year.