The response of Nigerian West African Dwarf goats to experimental infections with Haemonchus contortus.
One option for controlling haemonchosis in warm pastoral regions is improvement of resistance by selective breeding. Variation in acquired immunity to H. contortus and immunological correlates of infection were studied in West African Dwarf (WAD) goats. Following exposure to 5000 L3, 63 per cent of the inoculum established but 77 per cent of established worms were expelled by week 5. All infected animals were anaemic (day 14). When exposed to 2000L3, 36 per cent of the inoculum was still present (day 35) with no loss by day 49. Persisting primary infection worms survived a superimposed challenge (day 35), but their growth was slowed and resistance to challenge was significant. Most goats showed eosinophilia and parasite-specific IgG responses to primary infection, but only eosinophilia increased after challenge. No consistent associations were found between parasite burden and any immunological measures of infection, but parasite egg counts showed considerable variation. Overall, our results suggest that resistant genotypes exist among the WAD goat population.
Fakae
B B
BB
Department of Veterinary Parasitology and Entomology, University of Nigeria, Nsukka, Nigeria.
Chiejina
S N
SN
Behnke
J M
JM
Ezeokonkwo
R C
RC
Nnadi
P A
PA
Onyenwe
W I
WI
Gilbert
F S
FS
Wakelin
D
D
D000818:Animals; D001835:Body Weight; D004906:Erythrocyte Count; D015511:Goat Diseases / Q000097:blood / Q000469:parasitology / Q000503:physiopathology*; D006041:Goats; D006188:Haemonchiasis / Q000097:blood / Q000503:physiopathology / Q000662:veterinary*; D006189:Haemonchus / Q000302:isolation & purification*; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D009549:Nigeria; D010270:Parasite Egg Count / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology; D013997:Time Factors
D007074:Immunoglobulin G