Current status and countermeasures of chicken leucocytozoonosis in Japan
2007
Sakai, T.(Toshio Sakai Poultry and Livestock Clinic Ltd., Sakura, Chiba (Japan))
From the results of this investigation, the numbers of the breaking out of Chicken leucocytozoonosis have decreased in Japan. However, it still remains in the laying hen which are kept in open houses in the paddy field at the mountain area. This result is similar with the former reports. For exterminating harmful insects, the aerial spray of insecticide by helicopter has been done in paddy fields that is the biotope of Culicoides arakawae ; the vector of Chicken leucocytozoonosis. However, it was thought that the influence of the aerial spray may not to reach to those areas. Generally, clear subject is done from the middle of June to the end of July, and subject agrees with the generation time of Chicken leucocytozoonosis. It is also suggested that many of millraces in paddy fields that are the spawning ground of C. arakawae have been maintained by concrete which influence the total number of C. arakawae. It was thought the change in style of the poultry house from the open to windowless or semiwindowless for preventing C. arakawae was also effective to the prevention of Chicken leucocytozoonosis. More over, when we use insecticide for controlling C. arakawae, we must consider about 'The Japanese Positive List System for Agricultural Chemical Residues in Foods' which enforced on May 29, 2006. From this reason, it is also recommended to use physical methods such as ventilation with a large-scale fan and the light traps after the sunset. The genetically modified vaccine against Chicken leucocytozoonosis is effective during productive period of laying hen, but it must be used under consideration because it is expensive and takes the time of administration.
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