An investigation on the supplementation of rosemary volatile oil to the laying quail diets

Abstract

The purpose of the current study was to detect the effects of different levels of rosemary volatile oil (VO) supplemented to laying quail diets on performance, egg quality parameters, and egg yolk oxidative stability. In this study, a total of 105 laying quails (Coturnix coturnix Pharaoh) at the age of 6 weeks were used and 3 main groups were formed, each containing 35 quails. Also, each main group was separated into 5 replicates containing an equal number of quails. Quails were fed a control diet without rosemary VO or diets which were containing at different levels (200 or 400 mg/kg) of rosemary VO supplemented to the control diet. At the end of the study, which was continued for a total of 56 days, no significant difference was found in the feed intake, feed efficiency and egg weights among the control and experimental groups. The supplementation of rosemary VO at the levels of 200 and 400 mg/kg to the diets caused an increase in quails' egg production (P<0.01). However, there was no effect on the exterior and interior egg quality parameters. A significant decrease in malondialdehyde (MDA) levels in egg yolk were observed with both levels of rosemary VO at storage (+4 0C) for 7 (P<0.001) and 28 (P<0.01) days. Considering these data, it was concluded that rosemary VO can be supplemented to laying quail diets as a natural antioxidant without negatively affecting performance and egg quality parameters.