Adverse effects of Escherichia coli infection of turkeys were not alleviated by supplemental dietary vitamin E

Department of Animal Science, Iowa State University, Ames 50011-3150, USA.

Two experiments were conducted to determine the influence of dietary vitamin E on the response of young male turkeys to Escherichia coli infection. A complete factorial arrangement of two concentrations of supplemental dietary vitamin E (12 or 300 IU/kg as dl-alpha-tocopheryl acetate) and infection or no infection of turkeys with E. coli was used in both experiments. In Experiment 1, each dietary treatment was fed to four pens of turkeys from 1 to 28 d of age. At 28 d, turkeys in two pens per dietary treatment received an injection of 3.0 x 10(7) E. coli cells into the left and right thoracic air sacs. All turkeys were necropsied 7 d after E. coli injection and the incidence and severity of lesions in air sacs, lungs, pericardium, and liver were determined. The same dietary vitamin E treatments were used in Experiment 2. Each diet was fed to eight pens of turkeys from 1 to 47 d of age. At 47 d, turkeys in four pens per dietary treatment received an injection of 3.0 x 10(7) cells of the same E. coli used in Experiment 1 into the left and right thoracic air sacs. All turkeys were necropsied as in Experiment 1 at 54 d of age. Weight gain and efficiency of feed utilization were impaired markedly by E. coli infection during the 7 d after injection. Livability also was decreased by E. coli infection in Experiment 1 but not in Experiment 2. Adverse effects of E. coli on performance and livability were not affected by dietary vitamin E concentration. Lesions observed in turkeys that received E. coli injection ranged from mild to severe, with the most severe lesions observed in air sacs. Lung lesions were observed frequently but were less severe than in air sacs. Dietary concentration of vitamin E had no effect on incidence or severity of lesions in air sacs or lungs. Overall, the results of these experiments show that adding 300 IU of vitamin E/kg of diet did not alleviate the adverse effects of E. coli infection in young turkeys.