EFFECT OF DIETARY SUPPLEMENTATION OF POT MARIGOLD FLOWER POWDER AND EXTRACT (CALENDULA OFFICINALIS) ON NUTRIENT DIGESTIBILITY, PERFORMANCE, SERUM BIOCHEMISTRY, ANTIOXIDANT PARAMETERS, IMMUNE RESPONSE AND SOME GUT BACTERIAL COUNT OF LAYING JAPANESE QUAIL

: The aim of this study was to investigate the influence of Calendula officinalis flowers either as a powder (COP) or as an extract (COEx) on productive, digestion enzymes, nutrient digestibility coefficients, egg yolk cholesterol, serum metabolites, gut bacterial content, antioxidant capacity and immunological traits in laying Japanese quail. 504 hens (168 males and 336 females), at 9 th weeks of age were randomly distributed to seven experimental treatments, with six replicates of 12 birds each (four males and eight females). The first treatment was received a basal diet (control), groups from two to four fed on the basal diet supplemented with 0.6, 0.9 and 1.2 % COP, respectively. While, groups from five to seven were fed on basal diet supplemented with 150, 200 and 250 ppm COEx, respectively. Hens fed with 1.2% COP, 200 and 250 ppm COEx levels had significantly (p ≤ 0.001) higher egg number, egg production %, egg weight, and egg mass with the best feed conversion ratio without holding significant effect on feed intake. Egg yolk cholesterol was significantly (p ≤ 0.001) decreased in quails treated with 250 ppm COEx 1.2 % COP and 200 ppm COEx, respectively. Serum biochemistry (total cholesterol, TG, HDL and LDL), liver functions, antioxidant parameters, immune response and some gut bacterial count ( Lactobacillus ) were significantly (p ≤ 0.001) improved by some treatments. Digestive enzymes were significantly (p ≤ 0.001) improved by treatments with COP and COEx especially at 250 pm COEx. Finally, quails fed diets containing 0.6 % COP and 250 ppm COEx had significantly (p ≤ 0.001) the highest nutrient digestibility percentage. The present study concluded that the dietary supplementation with 200 and 250 ppm COEx to laying quail improved digestive enzymes, digestion of nutrients, productive performance, serum biochemistry, immunological parameters, antioxidant capacity, and gut microbial content.