title: The effect of vitamin A deficiency and Newcastle disease on lymphoid cell systems in chickens.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002060:Bursa of Fabricius / Q000276:immunology; D002452:Cell Count; D002645:Chickens; D007111:Immunity, Cellular; D008214:Lymphocytes / Q000276:immunology*; D009521:Newcastle Disease / Q000150:complications / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology; D013997:Time Factors; D014802:Vitamin A Deficiency / Q000276:immunology*