Abstract: The most important genus of thyme is thymus vulgaris known as a garden herb of thyme, which its biologic and pharmacologic effects include: expectorant, antiseptic, anticough, and also anti whooping cough. The recent studies show that thyme has significant effects too, on typhoid, diphtheria, colibacillus, pneumonic bacteria, staphylococcal, streptococcal bacteria, and also has antifungal and antioxidant effects. In this research, 600 day old LOHMAN broilers in 5 groups of 30 selected as experimental and control groups; and in all of these groups vaccination process and also determination of the final weight (FCR) have been used, which in experimental group different doses of essence have been received and after vaccination the samples were taken, and study process of hystopathological changes was done. Regarding to findings and statistical studies which were done SPSS software, the trachea edema factors, tracheitis, pulmonary edema, bronchitis, have been surveyed. In the results obtained from the 6th day onwards IB vaccine (H120) of all above cases experimental group reduced by increasing dose.
Adel Feizi, Farhad Dadian and Mehrdad Nazeri, 2012. The effect of thymus vulgaris volatile oils in controlling of the complications resulted from spray of H120 vaccine in broiler chicks. Journal of Animal and Veterinary Advances, 11: 357-360.