GLOBULE LEUKOCYTES IN THE LUMEN OF THE SMALL-INTESTINE AND THE RESISTANCE STATUS OF SHEEP INFECTED WITH PARASITIC NEMATODES

The presence of globule leukocytes in the lumen (LuGLs) of the small i ntestine was studied in Romney sheep reared parasite free and then exp erimentally infected or immunized with Trichostrongylus colubriformis infective larvae, or naturally infected when grazed on pasture. It was discovered that high numbers of LuGLs were associated with both paras itic infection and the sheep protective immune response. A high positi ve correlation was observed between LuGLs and tissue globule leukocyte s. The highest correlation (r = 0.92) observed was between larval migr ation inhibition (LMI) and numbers of LuGLs. This was the only correla tion between LMI and other parameters studied. Significant positive co rrelations were also observed between LuGLs and IgG(1) and eosinophils . There was a negative correlation between LuGLs and the number of par asites in the intestine and parasite egg production. Progeny of geneti cally resistant and susceptible sires had significantly different abil ities to produce LuGLs.