BREEDING AND GENETICS Immune Competence of Chicks from Two Lines Divergently Selected for Antibody Response to Sheep Red Blood Cells as Affected by Supplemental Vitamin E

Effects of dietary vitamin E on responses to SRBC antigens and Escherichia coli infection were stud- ied in chicks from White Leghorn lines selected for 24 generations for high (HAS) and low (LAS) antibody re- sponses to SRBC. Chicks were fed corn-soybean diets consisting of either high (300 IU per kg feed) or low (10 IU per kg feed) concentrations of vitamin E from the day of hatch through the end of experiment. The LAS chicks were heavier than the HAS chicks at 14 d of age and thereafter; there was no difference in BW between vitamin E concentrations. At 37 d of age, chicks were inoculated via the brachial vein with 0.1 mL of 0.25% SRBC suspen- sion. Antibody titers at 6 and 10 d after inoculation were higher in HAS than in LAS chicks. At 6 and 10 d after inoculation with SRBC, antibody responses were lower in LAS chicks fed the diet containing the higher vitamin