Faecal egg counts and immune markers in a line of Scottish Cashmere goats selected for resistance to gastrointestinal nematode parasite infection.
This study aimed to investigate the effect of selection for low faecal egg count (FEC) in Scottish Cashmere goats in comparison to a control line of unselected goats grazing the same pasture. Goats from generations F2 through to F9 were monitored for FEC, bodyweight, peripheral eosinophilia and IgG, IgA and IgE response against Teladorsagia circumcincta from the end of their first grazing season, through winter housing (during which a single artificial challenge dose of 10,000 drug susceptible T. circumcincta was given) and the following full grazing season. The study demonstrated that selected line animals excreted a significantly lower number of parasite eggs (P<0.01) in the majority of generations examined. Liveweight productivity was unaffected by selection. Although selected line animals had greater numbers of circulating eosinophils in many of the generations (four generations of males and six generations of females, P<0.05), there was no direct link between eosinophilia and reduced FEC. Immunoglobulin levels showed no consistent difference between selected and control lines. IgG, IgA and IgE levels were not different between lines over the whole dataset (P>0.05), although the selected line had significantly elevated or reduced levels (P<0.05) for all three within individual generations. There were significant associations between increased IgG and reduced FEC under artificial infection conditions (P=0.02). Increased IgA was also significantly associated with elevated FEC during the second grazing season (P<0.001). The study demonstrates that selection produced a line of goats with consistently reduced FEC compared with control animals, but did not identify a clear relationship between any of the immune markers measured and faecal egg output.
Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK. Electronic address: dave.mcbean@moredun.ac.uk.
David
D
McBean
Biomathematics and Statistics Scotland, James Clerk Maxwell Building, The King's Buildings, Peter Guthrie Tait Road, Edinburgh, UK.
Mintu
M
Nath
Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK.
Fiona
F
Kenyon
Biomathematics and Statistics Scotland, James Clerk Maxwell Building, The King's Buildings, Peter Guthrie Tait Road, Edinburgh, UK.
Karina
K
Zile
Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK.
David J
DJ
Bartley
Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK.
Frank
F
Jackson
D000818:Animals; D015415:Biomarkers / Q000097:blood; D001947:Breeding; D005243:Feces / Q000469:parasitology; D005260:Female; D020022:Genetic Predisposition to Disease; D015511:Goat Diseases / Q000235:genetics / Q000469:parasitology*; D006041:Goats; D008297:Male; D009349:Nematode Infections / Q000235:genetics / Q000469:parasitology / Q000662:veterinary*; D010270:Parasite Egg Count; D012641:Selection, Genetic
D015415:Biomarkers
Gastrointestinal nematodes; Goats; Selection