Dr G. J. JhaMadhurendu Kumar Gupta2024-06-032024-06-031986https://krishikosh.egranth.ac.in/handle/1/5810209599It can be concluded from this work that the macrophages or the RE system has a pivotal role in protection against MD. Its depletion reduces the immunity to MD and stimulation leads to protection almost as much as by the vaccination itself. It remains to be found out if the vaccine also acts in the same way as activation of the RE system by the inert substances. Another interesting finding was that the LAI test could help in detection of the birds resistant or susceptible to MD. But its efficacy can differ from age to age. Hence its utility appears to be more in the third and fourth month of age when the disease is more likely to develop.EnglishThesis