Effect of Shirazi thyme on oxidant status and absorptive surface area of the intestine in cold-induced pulmonary hypertensive broiler chickens

The effect of Shirazi thyme as a medicinal plant on oxidant status (lipid peroxidation, protein oxidation, total antioxidant capacity and catalase activity) and absorptive surface area were measured in three segments of small intestine in cold-induced pulmonary hypertensive chickens. Birds were reared at 4 groups (thyme 0, 0.25, 0.5 and 1 % of diet) for 42 days. To induce pulmonary hypertension, the temperature was gradually decreased. The body weight was increased in thyme-0.25% birds in compared to control ones while it was decreased in thyme-1% birds. The feed consumption was only increased in thyme-1% birds. The feed conversion ratio was lower in thyme-0.25% birds and higher in thyme-1% birds than control ones. The duodenal and jejunal villus surface area was lower in thyme-1% birds than control ones while it was greater in the thyme-0.5% birds. The ileal villus surface area and duodenal laminae properia thickness was also greater in thyme-0.5% birds. Lipid peroxidation was only decreased in the duodenum and ileum of thyme-0.5% birds compared to control ones, whereas it was increased in the duodenum and jejunum of thyme-1% birds. Catalase activity was only elevated in the duodenum and jejunum of thyme-1% fed chickens. Total antioxidant capacity was increased in the duodenum, jejunum and ileum of thyme-0.5% birds. It is concluded that Shirazi thyme has beneficial effects on growth performance, intestinal absorptive surface area / secretory system and pulmonary hypertension response at low doses (0.25 and 0.5% fed) whereas high dose of this plant may be toxic (1% fed).