The risks of Johne's disease entering and spreading within UK dairy herds.

摘要

This paper presents the results of the biosecurity risk assessments for 2296 dairy herds and Johne's disease biocontainment risk assessments for 1860 dairy herds that have undergone risk assessments during the period of April 2009 to September 2011 in the UK. Many UK dairy farms are at high risk of Johne's disease entering and spreading within their herds. The greatest risk of entry of Mycobacterium avium subsp. paratuberculosis (MAP) into dairy herds comes from purchasing or introducing cattle that are carrying the infection and may later become infectious. The highest risk of spread of Johne's disease come from contaminated environments to which highly susceptible calves have access. The most significant route of transmission is oral (calf access to contaminated udders, colostrum and milk).