Effects of Lavender Flower Distillation Residue Powder on Performance, Egg Quality and Yolk Antioxidant Capacity in Laying Japanese Quail

This study evaluated the effects of lavender flower distillation residue powder (LRP) as a dietary supplement on performance, egg quality and yolk oxidative status in laying Japanese quail. Seventy-five 24-week-old hens were allocated to three dietary treatments (0, 1 or 2 g/kg residue powder) for 10 weeks, with five replicate cages per treatment and five birds per cage. Feed intake increased at the inclusion level of 1 g/kg but decreased at 2 g/kg compared with the control group (p < 0.01), whereas egg production, egg weight, egg mass and feed conversion ratio were not affected (p > 0.05). Dietary supplementation reduced the proportion of damaged eggs (p < 0.05) and increased eggshell breaking strength (p < 0.01) in a dose-dependent manner. Yolk redness (a*) and Roche color score were higher in birds fed 1 g/kg of LRP (p < 0.01). Yolk radical-scavenging capacity (DPPH) increased at 1 g/kg (p < 0.01), while yolk malondialdehyde (MDA) concentration decreased with increasing inclusion level (p < 0.01). Overall, LRP may be used as a natural feed additive to improve eggshell integrity, yolk color and yolk antioxidant status in laying quail; however, the inclusion level should be carefully considered due to its contrasting effects on feed intake.