PRIMARY INFECTION OF KIDS WITH TELADORSAGIA-CIRCUMCINCTA - SUSCEPTIBILITY AND BLOOD-CONSTITUENTS

Fourteen male cross-bred Alpine x Saanen kids were infected with Teladorsagia circumcincta and four were used as controls. Three different levels of susceptibility to infection were apparent: resistant to infection and resilient to its adverse effects; intermediate (poorly resistant and poorly resilient); susceptible and relatively resilient. In the susceptible kids the establishment rate of infective larvae was twice as large and the nematode egg output five times greater during Weeks 4-8 after infection than in resistant kids. Susceptible kids harboured larger females with higher numbers of eggs in utero; the proportion of Teladorsagia trifurcata was higher in susceptible than in resistant kids. The blood constituents were significantly modified in infected compared with control animals: a lower number of leucocytes (particularly lymphocytes and basophils) and a higher complement activity were recorded in the latter. Compared with resistant kids, susceptible kids had higher counts of leucocytes, basophils and lower lymphocyte levels, less depleted complement pathway activity, higher pepsinogen values and lower levels of albumin and glucose.