Submitted to: Coccidiosis International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 2001
Publication Date: N/A
Technical Abstract: Infection with Eimeria maxima elicits a host response that includes production of free radicals NO. and O2.-, entities that can initiate oxidative stress in host tissues that may contribute to the pathogenesis of the disease. Several experiments have been conducted to determine whether high dietary levels of vitamin E acetate (VEA), can positively impact the pathological effects of E. maxima infection. In the first two experiments, commercial broilers vaccinated for infectious bronchitis and Newcastle's disease were fed diets containing VEA in a range from 13 ppm to 200 ppm. Chickens were given mild or severe infections with E. maxima. In neither infection were there beneficial effects of high dietary VEA (153 or 200 ppm) on weight gains, feed conversions, lesion scores at 6 days post inoculation (DPI), or on oocyst shedding. Plasma levels of NO2-+NO3- were not decreased. Percentage decreases in plasma VE (36% and 73%)(21% and 72%). A third experiment, conducted in non-vaccinated broilers, contrasted effects of 25 ppm and 225 ppm dietary VEA through 10 DPI of a moderate infection. 225 ppm VEA did not significantly reverse weight gain depression or reduce oocyst shedding. However, it significantly lowered lesion scores at 7 DPI, and reduced NO2-+NO3- levels at 5 and 7 DPI. Plasma VE and carotenoids were again similarly reduced (79% and 77% vs 76% and 77%)at 7 DPI. Results suggest that malabsorption of VEA during the acute phase of infection (5-7 DPI) may account for lack of effects of high dietary supplements.