Fig. 1From: Challenges for bovine viral diarrhoea virus antibody detection in bulk milk by antibody enzyme-linked immunosorbent assays due to changes in milk production levelsChanges in the size and milk production of Danish dairy herds from 2003 to 2010. Cows/Herd = median herd size (divided by 10); Milk/Herd = milk produced per herd (in 100,000 kg). Herds/Year = number of Danish dairy herds (in 1,000), which delivered milk from January to December; Milk/Year = national milk production (in billion kg of milk)Back to article page