Use of Different Sources of Dietary Fat and Green Tea Extract on Productive Efficiency, Gut Microbial Populations and Meat Quality of Broiler Chicks

In this experiment, a total of 360 one day-old female Ross 308 broiler chicks in a completely randomized design with a 2 × 3 factorial arrangement were allocated to 6 dietary treatments, each replicated five times with 12 birds per replicate. The included factors were two levels of green tea extract (GTE, 0 and 500 mg/kg diet) and three type of diets: 1- diet without dietary fat, 2- diet supplemented with soybean oil (SO) and 3- diet supplemented with Tallow (Ta). Use of GTE did not affect intestine microbial populations, intramuscular fat, oxidative stability of mat and performance in broiler chicken (p>0.05). Body weight gain and feed conversion ratio of chicks fed diet supplemented with SO or Ta was improved compared to the diets without fat (p<0.05). Use of SO compared to Ta and diets without fat led to higher and lower abdominal fat and carcass yield, respectively (p<0.05). GTE supplementation in diets high in fat was effective in decreasing abdominal fat percentage (p<0.05). The broilers that received green tea extract and soybean oil had a higher lactobacillus populations than those fed GTE with Ta (p<0.05). Dietary SO led to significantly greater intramuscular fat and thiobarbituric acid reactive substances (TBARS) values in thigh meat (p<0.05). Based on the findings of this study, despite the improvement in gut microbial populations and carcass fat content by GTE addition in diets high in un/saturated fats, its effect on intramuscular fat contents and muscle antioxidant capacity was not significant (p>0.05).