The effects of vitamin E and selenium (Se) supplementation on the immunity of hens vaccinated against a mixture of six swine-pathogenic Escherichia coli (EC) and avian encephalomyelitis virus (AEV) were studied. Antibody production (AbP) was evaluated in ninety 49 to 57-week-old H&N Nick Chick hens fed diets containing 14IU Vitamin E kg-1 (basal diet), 27, 59, 111, or 111IU vitamin E kg-1 + 0.56ppm Se supplementation. At 51 wks of age, half of the hens were vaccinated against EC, and all birds were vaccinated against AEV. At 53-weeks of age, the birds received a second dose of EC vaccine. Blood samples were collected weekly and serum was analyzed by ELISA for anti-EC IgY and was expressed as optical density (OD). Vaccinated hens had higher serum OD than the non-vaccinated hens (P<FONT FACE=Symbol>£</FONT>0.05). Vaccinated hens fed 27 and 59IU of vitamin E/kg had a higher (P<0.05) serum OD than hens fed 111IU + Se. Neither EC nor AEV seem to be appropriate models for the study of the influence of micronutrients on immune responsiveness of older hens.
avian encephalomyelitis; Escherichia coli; immunoglobulin; selenium; vitamin E
