ABSTRACT The present study aimed to investigate the potential utilization of orange peel essential oil (OPEO), as a natural feed additive in poultry nutrition. The impact of incorporating OPEO into the diets of laying quails was examined with respect to various performance criteria, including feed consumption and efficiency, as well as egg production, weight, and shelf life. A total of 120 female egg quails, aged 16 weeks, were allocated into three main groups, and fed with control rations supplemented with OPEO at levels of 0 mg/kg (control group), 200 mg/kg, and 300 mg/kg. Throughout the study, egg production was monitored on a daily basis, feed consumption was recorded every two weeks, and egg weights were measured twice a week on consecutive days. Moreover, the levels of malondialdehyde, a lipid peroxidation marker, in the egg yolks were quantified. The results indicated that the inclusion of OPEO in quail rations did not exert a significant influence on feed consumption and efficiency. However, OPEO supplementation had a positive impact on egg production and weight, leading to substantial increases in both crucial performance parameters. Furthermore, the study elucidated a statistically significant impact of OPEO on the levels of malondialdehyde in the egg yolks. In summary, the incorporation of OPEO into quail diets showcased remarkable efficacy in significantly augmenting egg yield and weight, while leaving feed consumption unaffected. These results highlight the potential of utilizing OPEO as a natural feed additive to improve the performance and egg quality of laying quails in commercial production systems.

One thousand two hundred and fifty sexed day-old broiler chicks obtained from a commercial hatchery were divided randomly into five treatment groups (negative control, antibiotic and essential oil combination (EOC) at three levels) of 250 birds each. Each treatment group was further sub-divided into five replicates of 50 birds (25 male and 25 female) per replicate. The oil in the EOC was extracted from different herbs growing in Turkey. The EOC at 24, 48 or 72 mg/kg diet and an antibiotic at 10 mg avilamycin/kg diet were added to the basal diet. There were significant effects of dietary treatments on body weight, feed intake (except at day 42), feed conversion ratio and carcass yield at 21 and 42 days. Body weights were significantly different between the treatments. The birds fed the diet containing 48 mg essential oil/kg were the highest, followed by those receiving the diets containing 72 mg essential oil/kg, the antibiotic, the negative control and the 24 mg essential oil/kg at day 42, respectively. From 1 to 21 and 1 to 42 days of age, feed conversion ratios were improved significantly by the supplementation with 48 and 72 mg essential oil/kg diet. The feed intakes were significantly different between the treatments at 21 days, but not at 42 days. Supplementation in excess of 48 mg EOC/kg had no additional beneficial effect on body weight, feed intake, feed conversion ratio and carcass yield. The EOC, a feed additive of natural origin, may be considered as a potential growth promoter in broiler production.