The Impact of Reduced Licorice Levels on Performance, Carcass Characteristics, Blood Constituents, Immunity, Intestinal Microflora, Intestinal Morphology, and Breast Muscle Fatty Acid Profile in Broilers

Background: Phytogenic feed additives derived from plants have gained special attention in poultry farming. This research was conducted to investigate the effects of low doses of licorice on broiler productivity. Methods: This experiment was conducted using ۱۲۰ commercially bred Ross ۳۰۸ broiler chickens at one day of age to investigate the effects of three different levels of licorice (۰, ۱۰۰, and ۲۰۰ mg/kg) in their feed. Results: The results showed that chickens fed with a diet supplemented with ۲۰۰ mg/kg of licorice (Glycyrrhizaglabra) had the highest feed intake (۹۴.۲۷ g/d) and weight gain (۵۷.۶۷ g/d), along with the most favorable feed conversion ratio (۱.۶۳ g/g). Moreover, this treatment had the highest economic returns (۳۴.۹۹ /m۲) and demonstrated the best European production index (۳۵۹.۸۱) compared to other treatments. It also led to a significant increase in certain carcass characteristics compared to the control group (P < ۰.۰۵). The effect of two different levels of licorice on some blood parameters (LDL/HDL ratio, LDL, VLDL, triglyceride, and glucose) was statistically significant (P < ۰.۰۵). The use of the licorice had no significant effect on the humoral immune system (P ≥ ۰.۰۵). Also, the inclusion of ۲۰۰ mg/kg of licorice resulted in the lowest population of Escherichia coli (۹.۱۸ CFU/g) the highest Bifidobacterium count (۹.۶۷۳ CFU/g), and the lowest ratio of saturated fatty acids to unsaturated fatty acids (۱.۲۷). Conclusion: The use of ۲۰۰ mg/kg of licorice (Glycyrrhizaglabra) as a dietary additive is recommended for Ross ۳۰۸ broiler chickens. The use of licorice can improve feed intake, weight gain, feed conversion ratio, cost per kilogram of live chicken, and production index at the end of the period.

Keywords:

Glycyrrhizaglabra , Yield , Antibody , Fatty acids , Chick