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

Fourteen male cross-bred Alpine x Saanen kids were infected with Telad orsagia circumcincta and four were used as controls. Three different l evels of susceptibility to infection were apparent: resistant to infec tion and resilient to its adverse effects; intermediate (poorly resist ant and poorly resilient); susceptible and relatively resilient. In th e susceptible kids the establishment rate of infective larvae was twic e as large and the nematode egg output five times greater during Weeks 4-8 after infection than in resistant kids. Susceptible kids harboure d 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 (particula rly lymphocytes and basophils) and a higher complement activity were r ecorded 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.