Effect of Thymus vulgaris extract on systemic antibody responses against Influenza and Newcastle disease vaccine in broiler chickens Journal title: Journal of Herbal Drugs Authors: Forough Talazadeh; Mansoor Mayahi; Hossein Najafzade Varzi; Hadis Norouzizade Subject(s): Medicine, Agricultural Science, Biotechnology, Botany, Genetics, Plant Sciences, Marketing, Pharmacology, Toxicology