Effect of Zataria multiflora boiss (thyme) extract on intestinal bacterial populations, meat cholesterol and carcass characteristics of broiler chickens fed diets with and without fat

This experiment was conducted using 240 one-day-old broiler chicks (Ross 308 strain) in a completely randomized design with 6 dietary treatments, each replicated 4 times with 10 birds/replicate. The dietary treatments were: 1, 2- diets without thyme extract (TE) with and without fat for the entire period of the experiment, 3, 4- diets with 0.5% TE with and without fat for the entire period of the experiment, and 5, 6- diets with 0.5% TE in last two weeks with and without fat. Weight gain (WG), feed intake (FI) and feed conversion ratio (FCR)) of chicks were measured as weekly basis. At day 42, two chicks were selected from each pen and slaughtered for microfloracount and thigh meat cholesterol measurement. Chicks fed diets supplemented with fat had higher body WG and FI, and lower FCR compared to diets without fat (P 0.05). As an overall conclusion, adding TE to the diets during the entire rearing period of the experimentled to significant reduction in thigh meat cholesterol in boiler chickens.