Growth and fecundity of Oesophagostomum dentatum in high-level infections and after transplantation into naive pigs.

This experiment was designed to examine the growth, proportion of stages, and fecundity of an Oesophagostomum dentatum population by transplantation of a known small number of worms from a high-density population into helminth-naive recipient pigs. Approximately 1,500 4-week-old worms [69% fourth-stage larvae (L4), 31% adult worms] were transplanted into each of 5 recipient pigs (group B), and these pigs, along with a group of 5 high-level-infection control pigs (group C), were killed at 4 weeks after transplantation to determine and compare the worm burdens. By 2 weeks after transplantation and throughout the experiment, fecal egg counts of group B exceeded those of group C and the fecundity of the worms was higher, though not statistically significantly so, in the transplanted worms. In the recipient pigs, all worms (approx. 70% establishment) had developed to the adult stage and were significantly longer than worms recovered from the group C pigs.