SAC Research

Bioactive are forages that can affect the resident or incoming worm population of grazing animals. Grazing on bioactive forages, such as chicory, birdsfoot trefoil, sulla, and sainfoin has been shown to reduce the negative effects of parasitism in sheep.

However, much needs to be learned about using bioactive forages in practical production systems.  It is not yet known whether bioactive forages act directly against incoming or established worms or whether they work indirectly by improving the nutritional status of parasitised animals. We have been looking at these questions in low input sheep production systems, where the preventative use of anthelmintic drugs is not allowed.

Research at SAC has shown that:

• Chicory was the best and most promising bioactive forage for the Scottish climate.
• Grazing on chicory for 2 weeks resulted in a reduction in numbers of adult worms in the intestines of growing sheep. 
• Grazing on chicory improved the performance and reduced the worm egg excretion in lambs grazing with their mothers.
• However, chicory consumption did not reduce the number of worm eggs excreted by ewes close to lambing. 
• The administration of conserved bioactive forages, such as sainfoin hay, resulted in a reduction of the number of worm eggs excreted by parasitised sheep.

Bioactive forages have direct effects on worms and short-term grazing on chicory or sainfoin may be useful for parasite control in sustainable systems of sheep production. Chicory plots could be incorporated in sheep grazing systems as deworming paddocks.