Two alternative remedies for controlling Haemonchus contortus in sheep (pumpkin kernel and garlic) were investigated. The experiment involved 18 4-month-old Merino ram lambs with six lambs per treatment group. The lambs were initially drenched to render them worm free, and then infected with 4000 L₃ H. contortus larvae, 2 weeks later. Four weeks after infection, faecal egg counts were performed and lambs were allocated into treatment groups and fed their respective diets (control, pumpkin kernel or garlic) for 2 weeks. The lambs were combined into a single group grazing pasture for the last week of the experiment. Faecal worm egg counts (WEC) were carried out weekly for 3 weeks following allocation to treatment diets. Clinical signs of infection observed included liveweight, body condition score and voluntary feed intake.

The pumpkin kernel treatment resulted in a 65.5% decrease in the initial level of WEC, but this increased back to the initial level as soon as animals came off treatment. The garlic resulted in a 64.4% decrease in WEC from the initial level and this increased slightly (to 25.5% of the initial level and 43.5% lower than the control) when the animals came off treatment, suggesting that there was a residual effect of the garlic and/or that the garlic had an effect beyond decreasing the fecundity of the parasites. There was no significant difference (P > 0.05) between treatments in liveweight, body condition score or voluntary feed intake. Throughout the experiment voluntary feed intake and liveweight increased while body condition scores remained stable.

We concluded that pumpkin kernel and garlic show potential for parasite control by affecting the fecundity of the parasites. Our results also indicate that with good nutrition lambs can cope with high parasite burdens and still be productive during the early stages of infection.