[Breed, line and sex differences of phagocytic activity in relation to broiler poultry resistance to Marek's disease virus].

The phagocytic activity was studied of 421 poulets and cocks of lines 66 and 77 of the Cornish breed, and lines 88 and 99 of the White Plymouth rock breed. Breed and linear differences were noticed in the changes of the phagocytic activity (phagocytic number and phagocytic index) with birds infected with the virus of Marek's disease. The rise of the phagocytic activity with lines 66 and 77 was slighter as compared with that of the White Plymouth Rock lines 88 and 99. Strongest were the changes in the phagocytic activity with birds that were strongly susceptible to Marek's disease, and slight est--with birds that were resistant to the disease. A trend of a better expressed phagocytic activity was noticed with the cocks of all investigated lines.