Effect of Using Lemon and Peppermint Essential Oils mixture to improve Growth Performance and Carcass characteristics of Japanese quail under heat stress Conditions.

This study evaluated the effects of lemon and peppermint essential oil (EO) combination on the growth performance and carcass characteristics of Japanese quails under heat stress. A total of 200 unsexed, healthy, seven-day-old quails were randomly assigned to four groups (50 birds each), with five replicates per group. The first group was reared under standard environmental conditions and served as the negative control (C-). The second group was subjected to high temperature stress (39–40°C for 6 hours/day), mimicking conditions in New Valley Governorate, and served as the positive control (C+). The third (T3) and fourth (T4) groups were also exposed to heat stress but received drinking water supplemented with a 1:1 mixture of lemon and peppermint EOs at 3 mL/L and 5 mL/L, respectively. Results showed that body weight, body weight gain, and feed conversion ratio significantly improved in EO-treated groups compared to controls. Feed intake was highest in T4 (679 ± 5.6 g), followed by T3 (636.2 ± 3.0 g), both significantly higher than C+ (448.9 ± 4.8 g). The C- group also had better intake (591.4 ± 3.1 g) than C+. Dressing percentage showed no significant differences (p = 0.243). Liver percentage was higher in T4 (2.745%) compared to C+ (2.185%, p = 0.05), and thymus percentage increased in EO-treated birds. Other carcass traits were unaffected. In conclusion, lemon and peppermint EO mixtures can be used as natural additives to alleviate heat stress and improve the productivity of quails in hot climates.