Milk Replacers and Bovine Spongiform Encephalopathy in Calves, Japan

As sources of the BSE infection in Japan, meat-bone-meal contaminated into cattle concentrates at feed plants and replacement milk containing animal fat imported from a BSE affected country are suspected. However, none of them has so far been specified conclusively. Geographical analysis using geographical information system was conducted to examine the possible relationship between the distribution of those suspected feed and birth places of BSE infected cattle in Hokkaido. As a result, there was no clear relationship found, because those feed were widely distributed within Hokkaido. However, the possible geographical linkage was suggested between the birth places and the replacement milk shipped in a specific period. Further investigations will be needed to clarify these possible linkages. Geographical analysis using GIS can assist the detection of risk factors of diseases by visualization of data. GIS becomes effective tools for epidemiological analysis of various diseases like BSE.