Effect Thymus vulgaris and Mentha pulegium powders on performance, carcass characteristics and some blood parameters of broilers under heat stress condition

    Heat stress worsens the performance through the physiologic changes in the body of the poultry. This study was designed to investigate the effect of Thymus vulgaris and Mentha pulegium powders on performance, carcass characteristics and some blood parameters of broiler chickens under heat stress. Two hundred one-day-old male Ross chicks were used in a completely randomized design with 4 treatments and 5 replicates each (10 birds for each replicate pen). Treatments were the control diet, 0.5% Mentha pulegium, 0.5% Thymus vulgaris and 0.5% mixture of both Thymus vulgaris and Mentha pulegium. The results showed that body weight gain was increased by consumption of all the experimental treatments during the finisher and whole the experimental periods as compared to control. Thymus vulgaris or mixture of both plants caused the decreased feed conversion ratio. The consumption of all experimental treatments increased the abdominal fat but the increment due to Thymus vulgaris consumption was greater than that of Mentha pulegium or the mixture of both plants. Mentha pulegium increased the blood triglyceride as compared to the other treatments. Moreover, consumption of both plants decreased the blood urea. Furthermore the birds receiving Thymus vulgaris had the higher hematocrit in comparison with control and the Mentha pulegium received birds. Totally, the consumption of Thymus vulgaris and Mentha pulegium alone or together causes the better body weight gain and feed conversion ratio probably through the improvement in feed digestion.