Effect of Licorice as an Alternative to Antibiotics on Productive, Egg Quality and Yolk and Blood Lipid Profile of Laying Japanese Quail

Abstract

A total number of one hundred and eighty Japanese quail birds (120 females and 60 males), 9-weeks old were randomly divided into five groups, 36 birds each and each treatment was replicated four times with 9 birds in a completely randomized design. Dietary treatments were as follows: basal diet only without supplementation and served as a control group, basal diet + 100 mg Tylosine /kg diet, basal diet + 250 mg licorice /kg diet, basal diet + 500 mg licorice /kg diet and basal diet +1000 mg licorice /kg diet. The results showed that dietary supplementation with different feed additives had insignificant effect on egg laying rate, egg number, average egg weight, egg mass and feed conversion ratio compared with control group. The percentage of egg shell thickness was significantly (P ≤ 0.001) increased by supplementation with Tylosine and licorice in compare with control group. Serum total lipids, total cholesterol and low density lipoprotein (LDL) were significantly (P ≤ 0.001) decreased due to addition of different feed additives. Yolk total lipids was significantly (P ≤ 0.001) decreased with dietary supplementation of licorice root powder and Tylosin in the diets. Also, significant (P ≤ 0.01) decrease in egg yolk cholesterol was recorded in the group fed with 500mg licorice in comparison with anther treatments. In conclusion, dietary inclusion of licorice powder could be applied as alternatives to in-feed antibiotics for laying Japanese quail diets.