Inhibition of bovine bone marrow granulocyte/macrophage colony formation in vitro by serum collected from cattle infected with Trypanosoma vivax or Trypanosoma congolense.

Serum collected from cattle infected with Trypanosoma vivax or Trypanosoma congolense inhibited bovine granulocyte/macrophage colony formation in methyl cellulose cultures. Maximum inhibition was caused by serum collected two and three weeks post infection. The degree of inhibition appeared to be related to the degree of parasitemia. Inhibition of erythroid colony formation by serum collected from these animals was not observed.