Effect of thyme, garlic and caraway herbal extracts on blood parameters, productivity, egg quality, hatchability and intestinalbacterial population of laying Japanese quail

BACKGROUND: In the current Iranian poultry industry, antibioticsare the most frequently used additive in poultry feedsto increase productivity. The negative effects on human health,resulting from the consumption of chicken whose feeds containantibiotics, makes finding an appropriate alternative of greatimportance. As a result of their nature, herbal extracts couldbe specifically considered for this purpose. OBJECTIVES: Thisstudy aimed to find an appropriate and harmless feed additiveto increase the quality and quantity of poultry eggs. METHODS:A completely randomized design including 4 treatments, 4 replicationsand 4 birds in each experimental unit was applied.Herbal extracts were added to drinking water of treatments inratio of 1:1000, with the control group containing no additivesin their water. The number and weight of produced eggs weremeasured on a daily basis, feed consumption on weekly basisand the egg quality, yolk cholesterol, hatchability and intestinalbacterial population were measured at the end of experimentafter 8 weeks. RESULTS: Herbal extract treatments showedno overall effect on quality and quantity of produced eggs incomparison with control; however, the thyme and garlic extractsreduced the cholesterol of serum and yolk relative to thecontrol. Herbal extracts did not significantly affect the hatchabilityof fertile eggs. The herbal extracts caused a significantdecrease in the intestinal bacterial population of laying quails.CONCLUSIONS: The garlic extract had the most decreasing effecton the cholesterol of serum and egg yolk. Furthermore,thyme extract had the most decreasing effect on the intestinalbacterial population.

Keywords:

blood parameters , eggs quality and quantity , herbal extracts , Japanese quail