Recently chicory has been found to have some interesting and even mysterious attributes when consumed by small ruminants such as sheep, goats and deer. Mark Thomas with Barenbrug USA told me that it seems to reduce parasites in sheep that graze on chicory in New Zealand.
“Sheep are wormy critters and need to be treated with de-worming medications every month when grazing in standard grass and legume pastures,” Mark said. “However, when sheep graze on pastures where chicory is present, we have found they only need worming once a year. This may be due to the unique tannins that chicory contains, but we can’t say for sure yet.”
http://www.qdma.com/what-we-do/articles/food-plotshabitat/chicory/
I have heard the same thing about tobacco!