Weight gain of calves during natural lungworm challenge infection is non-linearly related to previous infection history.
Calves, previously subjected to different rates of artificial lungworm infection for 10 weeks, were challenged with a natural lungworm infection on pasture after a 6-week housing period. The results showed a parabolic relationship between the effect of the natural challenge on weight gain and the previous rate of artificial infection. The highest average daily weight gains were observed in the calves previously subjected to intermediate rates of artificial infection. The results suggest the existence of an optimal rate of initial infection at which there is sufficient development of immunity to resist the pathogenic effects of reinfection without a concomitant penalty on weight gain.
Boon
J H
JH
Department of Fish Culture and Fishery, Agricultural University, Wageningen, Netherlands.
Ploeger
H W
HW
D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000209:etiology* / Q000276:immunology / Q000473:pathology*; D003371:Cough / Q000209:etiology / Q000662:veterinary; D004021:Dictyocaulus / Q000276:immunology; D004022:Dictyocaulus Infections / Q000209:etiology* / Q000276:immunology / Q000473:pathology*; D005243:Feces / Q000469:parasitology; D007814:Larva / Q000276:immunology; D008297:Male; D012119:Respiration; D013997:Time Factors; D015430:Weight Gain
D000909:Antibodies, Helminth