AN ATTEMPT TO IMPROVE THE PRODUCTIVE PERFORMANCE, HATCHING TRAITS AND BLOOD INDICES OF LAYING HENS DURING SUMMER SEASON BY ADDING LICORICE TO THE DIET

: This study aimed to evaluate the effectiveness of dietary licorice supplementation on productive and reproductive performance with physiological response of Inshas local chicken strain in summer months. A total of one hundred and ninety two laying hens of Inshas local strain at 36 weeks of age were housed in floor pens and randomly distributed into four treatment groups. Each treatment consisted of 48 females in three replicates, with 16 hens per replicate. Birds in control group were fed on a basal diet without any additives, while, other treatments were fed basal diet supplemented with 0.5% , 1.0 % and 1.5 % licorice powder, respectively. The experiment was conducted under summer condition in Egypt and commenced eight weeks through July and August months. According to the results, supplementation the diets of laying hens with licorice powder significantly increased productive performance (egg production, egg weight and egg mass). Also, feed conversion ratio was improved for all treatments compared to control group, while there were no significant differences with regard to feed consumption. In addition, all studied concentrations of licorice powder significantly improved percentages of fertility and hatchability of fertile eggs compared to control. Besides, concentration of 1 and 1.5% licorice powder significantly enhanced hatched chick weight compared to those for control group. Moreover, some egg quality traits such as yolk index, shell thickness and Haugh unit had been significantly improved with all concentrations of licorice powder supplementation, while yolk colour had been improved with 1.0 % and 1.5 % licorice powder only. Values of s s , Hb, globulin, total antioxidant capacity and HDL were significantly increased by supplementing the diet with all experimental concentrations of licorice powder compared with those for control. Moreover, values of packed cell volume and plasma calcium represented the same significant increase response of licorice except that with 0.5% , while, H/L ratio, total lipids, cholesterol and LDL were significantly decreased due to all studied licorice concentrations compared to control. In conclusion, supplementing the diet of laying hens in summer season with concentrations of 1.0 or 1.5 % licorice powder could be a good tool for maximizing productivity and reproductivity coincided with improving blood parameters and lipid profile.