Table 3.

Effect of vitamin E on chicken immune system and microbial pathogens.

Effect on the immune system and microbial pathogens	Dose	Host	Reference
Decrease of IL-6 mRNA	220 IU/kg	Broiler chickens	Kaiser et al., (2012)
Reduced liver expression levels of IL-6 and heat shock protein 70 (HSP70)	100 IU/kg	Broiler chickens	Jang et al., (2014)
More peripheral blood CD4+ and CD8+ T cells	80 IU/kg	Broiler chickens	Abdukalykova et al., (2008)
Increased lymphocyte populations in the thymus and increased plasma cell numbers in the spleen, cecal tonsils, and ileum	447 IU/kg	Broiler chickens	Khan et al., (2008)
Elevated numbers of peritoneal macrophages	164 and 328 IU/kg	Broiler chickens	Konjufca et al., (2004)
Increased antibody titers to an IBV vaccine	100 IU/kg	Broiler breeder	Khan et al., (2014)
Increased anti-NDV antibody	200IU/kg	Broiler chickens	Singh et al., (2006)
Lower mortality and increased weight gain in chickens challenged with E. tenella	100 IU/kg	Broiler chickens	Colnago et al., (1984)
IgA, IgM, and IgY increased at 2 wk after challenge with S. enteritidis, while IL-1β, IL-6, and mortality decreased	30 IU/kg	Laying hens	Liu et al., (2019)
Higher weight gain and reduced mortality when challenged with IBDV	178 IU/kg	Broiler chickens	McIlroy et al., (1993)

Abbreviations: IL-6, interleukin-6; IBV, infectious bronchitis virus; IL-1β, interleukin-1β; IBDV, infectious bursal disease virus.