Since few studies have been done on the effects of thyme on ruminants [1, 2] , this study aimed to investigate the effect of thyme on performance and some blood parameters were determined in lambs of different ages. This factorial experiment in a completely randomized design with two factors, each with two levels is the age and value of thyme was implemented. In this study, 20 male lambs Farahani for 4 groups of 5 animals at an average initial weight of 35/02 ±20 in two different age with an average of 5.5 months and a year were used. The study for 2 months in research stations Arak University Department of Animal Science. The treatments consisted of: 1- 5/5 month-old lamb diets, no powder, thyme, 2- diet containing 20 grams of dried thyme 5/5 months for lambs; 3- Annual lamb diets, lack of thyme powder; 4- Diet with 20 grams of dried thyme for lambs one year. The results showed that use of the herb thyme significant effect on growth performance and blood biochemical parameters were Farahani male lambs (p>0/05).
