Dose-response effects of Tenebrio molitor oil dietary supplementation on production performance, egg quality, and economic outcomes in Japanese quail layers under tropical conditions.

Feed cost volatility associated with conventional lipid sources such as primarily soybean oil, palm oil, and animal fats; poses a persistent challenge to economically viable poultry production in tropical and resource-constrained regions. Mealworm oil (MWO), derived from Tenebrio molitor larvae, offers a nutritionally relevant lipid supplement with a favourable unsaturated fatty acid profile; controlled evidence for its supplementation in laying quail systems, and particularly formal economic evaluation, remain limited. This study evaluated dose-response effects of graded MWO supplementation (0%, 0.5%, 1.0%, 1.5%) on egg production performance, egg quality, reproductive organ morphology, and economic outcomes in Japanese quail layers (Coturnix japonica). A total of 200 eleven-week-old females were allocated to four dietary treatments (50 birds per treatment; five replicates of ten birds each) in a completely randomised design; in T1-T3, corn starch was replaced isoenergetically by MWO at 0.5%, 1.0%, and 1.5%, respectively. Production data were collected over four weeks (weeks 12-15 of age). MWO supplementation produced dose-dependent improvements in egg production percentage, egg mass, and feed conversion ratio (FCR) across all experimental weeks; at week 15, T3 recorded an FCR of 2.57 ± 0.10 versus 4.49 ± 0.20 in T0 (P < 0.0001) and an egg production percentage of 74.24%. Albumen weight and Haugh units were significantly higher in T3 at all measurement weeks (P < 0.05), while yolk cholesterol declined progressively with increasing MWO inclusion; however, the absolute magnitude of this reduction was modest (approximately 5-9 mg/100 g). Eggshell traits were unaffected. Relative weights of the oviduct, ovary, and F-1 follicle were significantly greater in T3 at terminal assessment (week 15). A formal partial-budget analysis under local market conditions (Peshawar, Pakistan) indicated that the FCR improvement at 1.5% MWO reduced feed cost per dozen eggs from 80.98 ± 0.80 to 55.43 ± 0.76 PKR and generated the highest gross margin (ΔΠ = +727.3 PKR per replicate versus T0) despite the higher unit cost of MWO relative to corn starch. These results indicate that low-level MWO dietary supplementation has the potential to enhance quail layer performance and economic returns under similar conditions to those examined in this study. However, further validation at a commercial scale, along with re-parameterization across diverse tropical production environments, is necessary before making broader claims regarding its applicability.