Fructosamine concentration and resistance to natural, predominantly Teladorsagia circumcincta infection

Fructosamine con cent rations reflect protein status and because infection with Teladorsagia circumcineta can induce a relative protein deficiency, we examined the usefulness of fructosamine concentrations as markers of the i ntensity of infection in naturally infected lambs. Fructosamine concentrati on was a heritable trait and variation in fructosamine concentrations was a ssociated with differences in body weight, and a variety of parasitological variables; animals with increased fructosamine concentrations grew more qu ickly, had increased faecal egg counts in one of the three study years, had decreased pepsinogen concentrations and decreased IgA activity against 4th -stage larvae of T. circumcineta. Fructosamine concentrations were also ass ociated with variation in the subsequent acquisition of nematodes and in th e length of adult female T circumcineta; lambs with increased fructosamine concentrations had fewer nematodes but the mean length of adult female T. c ircumcineta was longer. Therefore fructosamine concentrations are potential ly useful indicators of the severity of nematode infection and may predict magnitude of subsequent infection.