Effect of a rosemary and oregano volatile oil mixture on performance, lipid oxidation of meat and haematological parameters in pharaoh quails

Abstract

1. This study was conducted to determine the utility of a volatile oil (VO) mixture in quail diets as a natural growth promoter. Different levels of VO mixtures, derived from rosemary and oregano, were added to a basal diet to determine the effects of the mixture on live weight (LW), live weight gain (LWG), feed intake, feed conversion ratio (FCR), carcase yield (CY), lipid oxidation level in thigh meat samples, and blood constituents. 2. A total of 880 one-day-old Pharaoh (Coturnix coturnix Pharaoh) quails, including both males and females, were divided into 4 groups containing 220 quails and treated as follows: (1) a control treatment with 0mg VO/kg of diet; (2) 100 mg/kg rosemary VO plus 100 mg/kg oregano VO (50:50%); (3) 140 mg/kg oregano VO plus 60 mg/kg rosemary VO (70:30%); and (4) 60 mg/kg oregano VO plus 140 mg/kg rosemary VO (30:70%). The diets were prepared fresh for each treatment. The experiment was carried out for 42 d. 3. The results of the study showed that the highest concentration of rosemary oil (140 mg/kg) caused a significant increase in live weight, live weight gain and carcase yields during the growing and finishing periods. However, feed intake and FCR were not significantly influenced by treatments. 4. The quails fed with rations containing the VO mixture derived from rosemary and oregano had reduced thiobarbituric acid levels (TBA) in raw breast meat samples at different storage times. There is possibly a synergistic effect between oregano and rosemary volatile oils in preventing lipid oxidation in stored meat. 5. In this study, the haemoglobin (PCV) and haematocrit values and the heterophile/lympohocyte (H/L) ratio increased in the blood samples taken from Treatment 2. 6. In conclusion, a volatile oil containing a mixture of rosemary and oregano oils could be a potential natural growth promoter for quails, depending on the plants from which the VOs were extracted, the dosage and the synergetic effects of the mixture.