Figure 1From: A survey of visitors on Swedish livestock farms with reference to the spread of animal diseasesa-b Number of visitors in different categories of herds. Results from a study dealing with frequency of indirect farm-to-farm contacts (Swedish livestock farms, 2006–2007). The bars represent the mean number of a) professional visitors, and b) non-professional visitors, by categories of species and herd size, black lines show the 95% confidence interval.Back to article page