The effects of different levels of Thyme (Thymus vulgaris L.) essential oils and Zinc sulphate on performance, immune system and some blood parameters in broiler chickens

This experiment was conducted to evaluate the effects of dietary Thyme (Thymus vulgaris L.) essential oils and Zinc sulphate (ZnSo4) on growth performance, carcass characteristics, immune response and some blood biochemical parameters in broilers and evaluate the effects of antibacterial thyme essential oils. In the laboratory section, an experiment was conducted to evaluate the effects of antibacterial thyme essential oils by using a completely randomized design with 5 treatments (0,100, 200, 300 and 400 ppm) and 4 replicates by disk diffusion method. Results indicated that, thyme essential oils at level 400 ppm reduced growth of Escherichia coli (PTCC 1399) and Clostridium perfringens (PTCC 1765). In farm experiment on broilers, a total of 200 one-day-old male chickens (Ross-308) were used in a completely randomized design with a 2×2 factorial arrangement including two levels of Zinc sulphate (0 and 300 mg/kg) and two levels of thyme essential oils (0 and 400 mg/kg) with 5 replicates (10 birds per replicate). Results showed that, feed intake, body weight gain and feed conversion ratio in total experiment period were not significantly (p0.05). The overall results of present experiment indicated that using thyme essential oils (400 mg/kg) and Zinc sulphate (300 mg/kg) in broiler diets, in levels of mentioned did not have any positive effects on measured traits.