Effect of natural feedstuffs added to a semi-purified diet on Eimeria tenella infection.

Experiments were conducted to study the effect of addition of natural feedstuffs to a semi-purified (SP) diet on Eimeria tenella infection of chickens. Chicks were fed the experimental diet throughout the experimental period and were orally inoculated with 200,000 sporulated oocysts of E. tenella at 14 days of age. Addition of corn, but not soybean meal, to a SP diet increased mortality and decreased body weight gain due to the coccidial infection in comparison with chickens fed the SP diet. Addition of corn gluten meal or replacement of poultry fat by corn oil or glucose by corn starch in the SP diet did not significantly change any of the parameters studied. Addition of 20% of corn fermentation solubles (CFS)-but not 20% of distillers dried grains with solubles, wheat bran, or rice bran-to the SP diet, resulted in significantly higher mortality from the coccidial infection. Addition of 5 or 10% of CFS to the SP diet significantly increased mortality in chicks compared to those fed the SP diet, but feeding the residue of CFS after extraction with chloroform-methanol followed by water did not increase mortality. These studies show that corn and CFS contain factors that enhance E. tenella infection in chicks fed a semi-purified diet, but other natural feedstuffs such as soybean meal do not.