Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2007
Publication Date: 5/4/2007
Citation: Jang, S.I., Jun, M., Lillehoj, H.S., Dalloul, R.A., Kong, I.K., Kim, S., Min, W. 2007. Anticoccidial effect of green tea-based diets against Eimeria maxima. Veterinary Parasitology 144:172-175. Interpretive Summary: Avian coccidiosis is caused by several distinct species of Eimeria, an intracellular protozoa belonging to the phylum Apicomplexa. Eimeria infection causes the extensive destruction of the intestinal epithelium which results in reduced feed efficiency, body weight gain, a temporary reduction in egg production, and the shedding of parasite oocysts. Although coccidiosis is mainly controlled by the use of chemotherapeutic agents, novel approaches are urgently needed due to the increasing emergence of drug-resistant parasite strains in commercial production settings. Feeding natural products or probiotics to animals that enhance their defense mechanisms could effectively reduce or prevent the need for therapy of these enteric infections. In this report, scientists at ARS collaborated with scientists at Gyeongsang National University in Korea to test the effect of green tea-supplemented diet on coccidiosis in broiler chickens. Green tea contains a number of polyphenolic compounds, collectively termed catechins that are considered to be anti-tumorigenic, anti-inflammatory, antioxidative, antiproliferative, antibacterial, antiviral, and anti-parasite effects. This study found that the green tea-based diets were effective in reduction of fecal oocyst output in chickens with infected with E. maxima. Considering that hosts are infected by ingestion and inhalation of sporulated oocysts in the feces or contaminated food, this finding is very important in that it reduces oocyst dissemination in the poultry house environment. This finding will provide valuable information on coccidiosis control to industry scientists.
Technical Abstract: Anticoccidial effects of green tea-based diets were evaluated in chickens following oral infection with Eimeria maxima a ubiquitous intestinal parasite of poultry that impares the growth and feed efficiency of infected birds. Five-week old chickens were assigned to four groups (GT 0.5%, GT 2.0%, infected and untreated, control non-infected), each composed by 15 chickens. The chickens were fed with ground green tea for 2 weeks ago prior to infection with 10,000 (per bird) sporulated oocysts of E. maxima. The effects of green tea were assessed by two parameters, fecal oocyst shedding and body weight gain. The green tea-fed chickens produced significantly less fecal oocysts (P < 0.05) when compared to the untreated and infected group. The green tea-based diets were not effective in protecting the lost of body weight caused by E. maxima infection when compared to the control group. This study is the first to demonstrate effects of green tea on the reduction of fecal oocyst shedding in chickens infected with E. maxima. This suggests a possible use as a natural feed additive.