Experimental Haemonchus contortus infection in three breeds of sheep.
Nine- to 10-month-old Florida Native, St. Croix and Dorset/Rambouillet sheep were infected with Haemonchus contortus. The primary infection was terminated by anthelmintic treatment 9 weeks later and animals were then reinfected with H. contortus. Dorset/Rambouillet sheep showed higher fecal egg counts and decreased packed cell volumes and plasma protein levels compared with the other two breeds during the primary infection. However, no breed differences were found in total worm burdens in either primary or secondary infection. Differences between breeds were also not detected in lymphocyte responsiveness to parasite antigen, H. contortus specific mucosal antibody levels, numbers of abomasal mast cells and globule leukocytes or abomasal histamine levels.
Department of Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
A M
AM
Zajac
S
S
Krakowka
R P
RP
Herd
K E
KE
McClure
D000818:Animals; D001947:Breeding; D002452:Cell Count / Q000662:veterinary; D004906:Erythrocyte Count / Q000662:veterinary; D005243:Feces / Q000469:parasitology; D005260:Female; D006188:Haemonchiasis / Q000097:blood / Q000276:immunology / Q000662:veterinary*; D006400:Hematocrit / Q000662:veterinary; D006632:Histamine / Q000032:analysis; D007113:Immunity, Innate / Q000235:genetics; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008213:Lymphocyte Activation; D008297:Male; D008407:Mast Cells; D010270:Parasite Egg Count; D012756:Sheep; D012757:Sheep Diseases / Q000097:blood / Q000276:immunology*; D014252:Trichostrongyloidiasis / Q000662:veterinary*
D007071:Immunoglobulin A, Secretory; D007075:Immunoglobulin M; D006632:Histamine