tetrameres americana cram (1927) populations in chickens infected with different dose levels. | three groups of 20-45 lohman brown chickens aged 3 weeks were orally infected with doses of 25, 100 and 400 tetrameres americana, respectively. fifteen chickens were kept as uninfected controls. every third week in a period of 12 weeks, 5-15 chickens were slaughtered and the proventriculi were examined for the presence of adult stages of t. americana. from day 21 post-infection, pooled feacal samples were examined for parasite eggs, whereas the weight gain of the chickens was monitored weekly. t ... | 2004 | 15381303 |