Individual estimated total worm burden of the two groups of lambs infected with 6000 Nematodirus battus infective larvae. The stacked bar chart shows the estimated total worm burden (reported as males (light grey), females (dark grey) and juveniles (black)) for each lamb in the fenbendazole (FBZ) treated (MNba2FBZ; 5 mg/kg FBZ body weight) and control (MNba2CON) groups. The control group (MNba2CON) estimated total number of worms ranged between 2350 and 5750, with an arithmetic mean of 3850 worms. The FBZ treated group (MNba2FBZ) estimated total number of worms ranged between 3050 – 4500 worms, with an arithmetic mean of 3850 worms. This showed a 0% efficacy with FBZ treatment.