Master of Science (MS)


School of Animal Science

Document Type



Parasites cause considerable economic losses in all fields of agriculture. In the poultry industry, coccidia infections are of major significance costing billions of dollars every year. Research on condensed tannins (CT) has been shown to be effective against various parasites such as gastrointestinal nematodes and Eimeria spp. in small ruminants. This study tested the effects of the CT containing forage, sericea lespedeza (SL), on broiler chickens infected with live Eimeria spp. oocysts. In Study 1, 300 Ross 708 broiler chicks were divided into 6 groups (negative control, positive control w/BioCox, 0% SL, 5% SL, 10% SL, 15% SL). In Study 2, 250 Ross 708 broiler chicks were divided into 5 groups (negative control, positive control w/BioCox, positive control w/Corrid, 0% SL, 10% SL). Chicks were grown for 18 days in battery cages. All groups, except the negative control, were infected with a high dose (approximately 100,000 oocysts per chick) of oocysts at day 4 via gavage. SL was fed to the appropriate groups from day 0 to day 18. Data analysis included fecal oocyst count (FOC), weight, feed conversion, lesion scoring and histopathology. Results from Study 1 indicated that 10% and 15% SL, significantly decreased FOC. Reduced body weight (BW) and feed conversion for all SL fed chicks were also noted. Lesion scoring was not of value. Histopathology suggested a potential mechanism of action of CT, in that only the SL fed chicks had developing stages in the intestinal mucosa. Therefore, CT may act to slow development allowing the immune response to mature. In Study 2, FOC was not affected by the 10% SL treatment. Reduced BW and feed conversion were also observed as in Study 1. Feeding broiler chicks, a diet containing SL may be beneficial for controlling Eimeria spp. infection, but production was negatively affected. Therefore, feeding SL should not be recommended at this time pending further research to address the production issues.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Miller, James