| Abstract: | The histological changes in the abomasal mucosa of pairs of worm-free ewes and lambs were compared at various stages after infection and reinfection with 350 Haemonchus contortus L3 per kg bodyweight. In terms of worm burdens the ewes were relatively resistant to reinfection compared with the lambs and the histological changes in the abomasum at most stages after infection were more marked in the adult animals. These included increases in the numbers of mast cells, globule leucocytes, eosinophils and IgA plasma cells in the mucosa. |
