Five experimental groups were established : negative control ( untreated , unchallenged ) ; positive control ( untreated , challenged ) ; a group medicated with 125 ppm lasalocid and challenged ; a group medicated with A. annua leaf powder at 1.5 % in feed and challenged ; and a group treated with the mixed oils of A. annua and Foeniculum vulgare in equal parts , 7.5 % in water and challenged .