Effect of Zataria multiflora boiss (thyme) extract and fat on meat quality, intestinal pH and serum antioxidant status of broiler chicks

In this experiment, 240 one-day-old broiler chicks were assigned to one of six dietary treatments in a completely randomized design. Each treatment replicated four times with 10 birds per replicate. The dietary treatments were: 1 and 2: diet without thyme extract (TE) with and without soybean oil (SO) for the entire period of the experiment; 3 and 4: 0.5% TE with and without SO for the entire period of the experiment; 5 and 6: 0.5% TE in last two weeks with and without SO. Supplementation of TE to the diets significantly decreased serum malondialdehyde concentration and increased gluthatione peroxidase activity (P0.05). Thyme extract supplementation to the diets caused significant reduction in gut pH (P0.05). Soybean oil addition to the diets did not have significant effect on malondialdehyde and cholesterol concentrations, and gluthatione peroxidase activity of broiler chick's serum (P>0.05). As an overall conclusion, adding TE to the diets throughout the entire experimental period led to improvement in antioxidant status, reduction in gut pH and serum cholesterol of broiler chicks.