Efficacy of sainfoin (Onobrychis viciifolia) pellets against multi resistant Haemonchus contortus and interaction with oral ivermectin: Implications for on-farm control.

•Efficacy of sainfoin on a multiresistant to anthelmintic strain of H. contortus.•Combining tannin-containing diet and oral administration of macrocyclic lactones could have negative consequences.•Need for further experiments to study the interactions between tannin containing diet and anthelmintic drugs.