[Phagocytic activity and antibody formation in relation to the resistance of poultry to fowl typhoid-pullorum...

Vulchanov's method (1954) was employed to study the phagocytic activity, and the classic method with the agglutination test served to follow up the production of antibodies. Some breed-associated differences were observed in the phagocytic activity and the normal serologic antibody titer prior to the infection with Salmonella pullorum and Salmonella gallinarum. Highest were the indices with the Leghorn breed, followed by the Cornish and Plymouth Rock breeds. Certain breed differences were also established between the size of changes taking place in the phagocytic activity following the infection of birds with Salmonella pullorum and Salmonella gallinarum. These indices were least changed with the Leghorn breed, more with Cornish, and most Plymouth Rock. There was a correlation between phagocytic activity and the average serologic titer. Higher indices of phagocytosis corresponded to higher average antibody titers.