Effect of probiotic and medicinal plant supplements on the production and egg quality of laying Japanese quail hens.

The present study was conducted to compare the response of laying Japanese quail hens to dietary supplementation with probiotic (Lacto-Sacc) and medicinal plant Thyme flowers (Thymus vulgaris ) through three-months experimental period. The response was measured in terms of productive performance, egg quality and chemical composition of the edible parts of egg, blood constituents, and digestibility of nutrients. A total of 150 laying Japanese quail hens which had been in production for 12 weeks were, randomly, allocated in a completely randomized design considering five treatments with three replicates and 10 samples in each. A group of them received a layer basal diet with no supplementation and served as control. The second and third groups were fed the control diet supplemented with 1.0 or 2.0 g of probiotic / kg diet, respectively. The fourth and fifth groups were fed the same control diet with a supplement of 1.0 or 2.0 g of Thyme flowers / kg diet, respectively. The results showed that the supplementation of 1.0 or 2.0 g probiotic / kg diet resulted in significant effect ( p ≤ 0.01 ) on the improvements of egg production, eggs mass / hen / day, egg weight and feed conversion ratio as compared to control laying hens. However, only slight numerical improvements, but not significant, were observed for means egg production, egg weight, egg mass and feed conversion ratio when birds were fed with 1.0 g Thyme flowers supplemented diet compared with control. Egg quality measurements were not affected by the dietary treatments. However, yolk cholesterol was significantly (p ≤ 0.01) decreased by adding 1 g of lacto-Sacc or 1 g Thyme flowers / Kg diet. Neither digestibility of ether extract, nitrogen free extract, crude fiber and organic matter nor energy utilization were affected by dietary treatments. However, probiotic supplementation to diets at 1.0 or 2.0 g / kg diet caused a pronounced increase in protein digestibility as compared to control. Notably, using 2.0 g probiotic Kg diet and 1.0 g Thyme flowers / Kg diet caused significant (P ≤ 0.05) decrease in plasma cholesterol and plasma total lipids, but they had no significant effects on other blood constituents.