Titlebook: Marek’s Disease; Scientific Basis and L. N. Payne Book 1985 Martinus Nijhoff Publishing, Boston 1985 diagnosis.oncology.pathology.vaccinati

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Pathology,ral agent of the disease was isolated, during the 1960’s. Since then the main pathological events that occur during the development of MD have been elucidated (3), usually from studies on young genetically-susceptible chickens infected experimentally with pathogenic strains of MD virus (MDV). These events are described in this Chapter.

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Book 1985 which killed one chicken in five, and which defied efforts to understand and control it for !lOre than 50 years, and one can begin to appreciate the interest Marek‘s disease has received. Canpound these characteristics with the finding of the causal herpesvirus, its recog­ nition as the neoplasm fi

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Genetic Resistance, successful selection for important production traits (5). Other workers reported similar success in selection for resistance (7,8), and these early studies prompted some poultry breeders to develop their own resistant strains (9).

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,Spread of Marek’s Disease, and mortality may reach 80% of a flock. However, it is a characteristic of the disease that its incidence varies greatly in infected flocks, and between houses and pens within a house on a single site (6). These variations can be greater than 10-fold.